We perform ongoing evaluations of our business, operational efficiency and cost structure, and implement restructuring actions as we deem necessary. In connection therewith, we recorded restructuring charges of $24.4 during the fourth quarter of 2016 consisting of employee termination costs resulting from changes to our operating model, and charges (including employee termination costs) related to our decision to exit the solar panel manufacturing business.
Our restructuring charges for the fourth quarter of 2016 consisted of cash charges of $5.4, primarily for employee termination costs relating to our Global Business Services and Organizational Design initiatives, and the closure of our solar panel manufacturing operations, and non-cash charges of $19.0, to write down our solar panel manufacturing equipment at our two solar locations to recoverable amounts. As we intend to sell this equipment, the recoverable amounts were based on their estimated fair values less costs to sell. We estimated these values based on external inputs, including recent market transactions and third-party estimates. We reduced the carrying value of our solar panel manufacturing equipment to these estimated fair values less costs to sell at the end of 2016. However, the recoverable amounts are subject to adjustment based on the actual results of our sales process. In addition, a substantial portion of this equipment is subject to finance leases. We intend to terminate these leases upon disposition of the equipment thereunder and settle our remaining lease obligations (which as of December 31, 2016 were $15.3) in 2017. Our restructuring charges of $31.9 for the full year 2016 consisted of cash charges of $10.7, primarily for employee termination costs including at our solar panel manufacturing operations and other exited operations, and non-cash charges of $21.2, to write down certain plant assets and equipment to recoverable amounts, including $19.0 related to our solar panel manufacturing business at our two locations. We recorded restructuring charges of $2.1 and $23.9, respectively, for the fourth quarter and full year 2015. Our restructuring charges for the fourth quarter of 2015 consisted of cash charges primarily for employee termination costs. Our restructuring charges for the full year 2015 consisted of cash charges of $19.5, primarily for employee termination costs at various sites, including headcount reductions in certain under-utilized manufacturing sites in higher cost locations, and non-cash charges of $4.4, primarily to write down certain equipment to recoverable amounts. These full year 2015 charges also included costs associated with the consolidation of two of our semiconductor sites in the second quarter of 2015, to reduce the cost structure and improve the margin performance of that business. Our restructuring provision at December 31, 2016 was $6.6 (December 31, 2015 -- $10.7) comprised primarily of employee termination costs.
The recognition of restructuring charges requires us to make certain judgments and estimates regarding the nature, timing and amounts associated with our restructuring actions. Our major assumptions include the number of employees to be terminated and the timing of such terminations, the measurement of termination costs, the timing and amount of lease obligations and any sublease recoveries from exited sites, and the timing of disposition and estimated fair values of assets available for sale, as applicable. We develop detailed plans and record termination costs for employees informed of their termination. For leased facilities that we intend to exit, the lease obligation costs represent future contractual lease payments and cancellation fees, if any, less estimated sublease recoveries. We may engage independent brokers to determine the estimated fair values less costs to sell for assets we no longer use and which are available for sale. We recognize an impairment loss for assets whose carrying amount exceeds their respective fair values less costs to sell as determined by such independent brokers. We also record adjustments to reflect actual proceeds received upon the disposition of these assets. At the end of each reporting period, we evaluate the appropriateness of our restructuring charges and balances. Further adjustments may be required to reflect actual experience or changes in estimates.
(b) Annual impairment assessment:
We conduct our annual impairment assessment of goodwill, intangible assets and property, plant and equipment in the fourth quarter of each year (which corresponds to our annual planning cycle), and whenever events or changes in circumstances indicate that the carrying amount of an asset, CGU or a group of CGUs may not be recoverable (triggering events). We recognize an impairment loss when the carrying amount of an asset, CGU or a group of CGUs exceeds its recoverable amount, which is measured as the greater of its value-in-use and its fair value less costs to sell. Prior to conducting our 2016 annual impairment assessment, we did not identify any triggering event during the course of 2016 indicating that the carrying amount of our assets or CGUs may not be recoverable, other than our decision in the fourth quarter of 2016 to exit the solar panel manufacturing business. In connection therewith, we recorded an impairment loss (as restructuring charges) on our solar panel manufacturing equipment in the fourth quarter of 2016 (see note 11(a)). We reduced the carrying value of our solar panel manufacturing equipment to its estimated fair value less costs to sell.
For our 2016 annual impairment assessment of goodwill, intangible assets and property, plant and equipment, other than the impairment described above, we used cash flow projections based primarily on our plan for 2017 and, to a lesser extent, on our three-year strategic plan and other financial projections. Our plan for 2017 is primarily based on financial projections submitted by our subsidiaries in the fourth quarter of 2016, together with inputs from our customer teams, and is subjected to in-depth reviews performed by various levels of management as part of our annual planning cycle. The plan for 2017 was approved by management and presented to our Board of Directors in December 2016.
In the fourth quarter of 2016, we performed our annual impairment assessment of goodwill, intangible assets and property, plant and equipment and determined that, other than the write down of our solar panel manufacturing equipment discussed above, there was no impairment as the recoverable amount of our assets and CGUs exceeded their respective carrying values.
In the fourth quarter of 2015, we performed our annual impairment assessment of goodwill, intangible assets and property, plant and equipment. We recorded non-cash impairment charges totaling $12.2, comprised of $6.5 and $5.7, against the property, plant and equipment of our CGUs in Japan and Spain, respectively. Such charges were primarily due to the reduction of our long-term cash flows projections for these CGUs as a result of reduced customer demand and challenging market conditions that we were experiencing in these CGUs at that time, and our assessment of the continued negative impact of these factors on the future profitability of these two CGUs. After recording the 2015 impairment charges, the carrying value of the property, plant and equipment held by each such CGU was reduced to approximate the fair value of its real property at the end of 2015.
We determined the recoverable amount of our CGUs as the greater of its expected value-in-use and its fair value less costs to sell. The process of determining the recoverable amount of a CGU is subjective and requires management to exercise significant judgment in estimating future growth, profitability, and discount rates, among other factors. The assumptions used in our 2016 annual impairment assessment were determined based on past experiences adjusted for expected changes in future conditions. Where applicable, we engaged independent brokers to obtain market prices to estimate our real property and other asset values. For our 2016 assessment, we used cash flow projections ranging from 1 to 7 years (2015 -- 3 to 10 years; 2014 -- 2 to 9 years) for our CGUs, in line with the remaining useful lives of the CGUs' essential assets. We generally used our weighted-average cost of capital of approximately 10% (2015 -- approximately 8%; 2014 -- approximately 10%) to discount our cash flows. For our semiconductor CGU, however, we applied a discount rate of 17% in 2014 through 2016 reflecting the higher risk and continued volatilities inherent with these cash flows, despite the new business awarded to this CGU in the past few years.
As part of our annual impairment assessment of goodwill, we also perform sensitivity analyses for the relevant CGUs in order to identify the impact of changes in key assumptions, including projected growth rates, profitability, and discount rates. Our goodwill balance at December 31, 2016 of $23.2 was comprised of $19.5 (December 31, 2015 -- $19.5) attributable to our semiconductor CGU and $3.7 attributable to our Karel acquisition. See note 4. For purposes of our 2016 impairment assessment of our semiconductor CGU, we assumed future revenue growth at an average compound annual growth rate of 7% over a 7-year period (2015 -- 9% over an 8-year period), representing the remaining life of the CGU's most significant customer contract. We believe that this growth rate is supported by the level of new business awarded in recent years, the expectation of future new business awards, and anticipated overall demand improvement in the semiconductor market based on certain market trend analyses published by external sources. We also assumed that the average annual margins for this CGU over the projection period will be slightly above our overall margin performance for the Company in 2016, consistent with the average annual margins we assumed for our 2015 impairment analysis. For our 2016 annual impairment analysis, we did not identify any key assumptions where a reasonably possible change would result in material impairments to our semiconductor CGU.
