Accounting Changes and Reclassifications (Policies)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Accounting Changes

Accounting Changes

Deferred Income Taxes — In November 2015, the Financial Accounting Standards Board (“FASB”) amended authoritative guidance associated with deferred income taxes. To simplify the presentation of deferred income taxes, the amended guidance requires that deferred tax liabilities and assets be classified as noncurrent in the statement of financial position. This eliminates the guidance to separate deferred income tax liabilities and assets into current and noncurrent amounts in the statement of financial position. The amendments to the authoritative guidance associated with deferred income taxes were effective for the Company on January 1, 2016; however, early adoption was permitted. The Company’s early adoption of this guidance in 2015 was applied retrospectively and did not have a material impact on our consolidated financial statements.

Reclassifications

Reclassifications

When necessary, reclassifications have been made to our prior period consolidated financial information in order to conform to the current year presentation.

Principles of Consolidation

Principles of Consolidation

The accompanying Consolidated Financial Statements include the accounts of WM, its wholly-owned and majority-owned subsidiaries and certain variable interest entities for which we have determined that we are the primary beneficiary. All material intercompany balances and transactions have been eliminated. Investments in entities in which we do not have a controlling financial interest are accounted for under either the equity method or cost method of accounting, as appropriate.

Estimates and Assumptions

Estimates and Assumptions

In preparing our financial statements, we make numerous estimates and assumptions that affect the accounting for and recognition and disclosure of assets, liabilities, equity, revenues and expenses. We must make these estimates and assumptions because certain information that we use is dependent on future events, cannot be calculated with precision from available data or simply cannot be calculated. In some cases, these estimates are difficult to determine, and we must exercise significant judgment. In preparing our financial statements, the most difficult, subjective and complex estimates and the assumptions that present the greatest amount of uncertainty relate to our accounting for landfills, environmental remediation liabilities, asset impairments, deferred income taxes and reserves associated with our insured and self-insured claims. Each of these items is discussed in additional detail below. Actual results could differ materially from the estimates and assumptions that we use in the preparation of our financial statements.

Cash and Cash Equivalents

Cash and Cash Equivalents

Cash in excess of current operating requirements is invested in short-term interest-bearing instruments with maturities of three months or less at the date of purchase and is stated at cost, which approximates market value.

Concentrations of Credit Risk

Concentrations of Credit Risk

Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents, investments held within our trust funds and escrow accounts, accounts receivable and derivative instruments. We make efforts to control our exposure to credit risk associated with these instruments by (i) placing our assets and other financial interests with a diverse group of credit-worthy financial institutions; (ii) holding high-quality financial instruments while limiting investments in any one instrument and (iii) maintaining strict policies over credit extension that include credit evaluations, credit limits and monitoring procedures, although generally we do not have collateral requirements for credit extensions. We also control our exposure associated with trade receivables by discontinuing service, to the extent allowable, to non-paying customers. However, our overall credit risk associated with trade receivables is limited due to the large number of diverse customers we serve. At December 31, 2015 and 2014, no single customer represented greater than 5% of total accounts receivable.

Trade and Other Receivables

Trade and Other Receivables

Our receivables, which are recorded when billed, when services are performed or when cash is advanced, are claims against third parties that will generally be settled in cash. The carrying value of our receivables, net of the allowance for doubtful accounts, represents the estimated net realizable value. We estimate our allowance for doubtful accounts based on historical collection trends; type of customer, such as municipal or commercial; the age of outstanding receivables; and existing economic conditions. If events or changes in circumstances indicate that specific receivable balances may be impaired, further consideration is given to the collectability of those balances and the allowance is adjusted accordingly. Past-due receivable balances are written off when our internal collection efforts have been unsuccessful. Also, we recognize interest income on long-term interest-bearing notes receivable as the interest accrues under the terms of the notes. We no longer accrue interest once the notes are deemed uncollectible.

Other receivables at December 31, 2015 and 2014 include receivables related to tax payments in excess of the provision of $439 million and $255 million, respectively.

Parts and Supplies

Parts and Supplies

Parts and supplies consist primarily of spare parts, fuel, tires, lubricants and processed recycling materials. Our parts and supplies are stated at the lower of cost, using the average cost method, or market.

Landfill Accounting

Landfill Accounting

Cost Basis of Landfill Assets — We capitalize various costs that we incur to make a landfill ready to accept waste. These costs generally include expenditures for land (including the landfill footprint and required landfill buffer property); permitting; excavation; liner material and installation; landfill leachate collection systems; landfill gas collection systems; environmental monitoring equipment for groundwater and landfill gas; and directly related engineering, capitalized interest, on-site road construction and other capital infrastructure costs. The cost basis of our landfill assets also includes asset retirement costs, which represent estimates of future costs associated with landfill final capping, closure and post-closure activities. These costs are discussed below.

Final Capping, Closure and Post-Closure Costs — Following is a description of our asset retirement activities and our related accounting:

• Final Capping — Involves the installation of flexible membrane liners and geosynthetic clay liners, drainage and compacted soil layers and topsoil over areas of a landfill where total airspace capacity has been consumed. Final capping asset retirement obligations are recorded on a units-of-consumption basis as airspace is consumed related to the specific final capping event with a corresponding increase in the landfill asset. Each final capping event is accounted for as a discrete obligation and recorded as an asset and a liability based on estimates of the discounted cash flows and capacity associated with each final capping event.

• Closure — Includes the construction of the final portion of methane gas collection systems (when required), demobilization and routine maintenance costs. These are costs incurred after the site ceases to accept waste, but before the landfill is certified as closed by the applicable state regulatory agency. These costs are recorded as an asset retirement obligation as airspace is consumed over the life of the landfill with a corresponding increase in the landfill asset. Closure obligations are recorded over the life of the landfill based on estimates of the discounted cash flows associated with performing closure activities.

• Post-Closure — Involves the maintenance and monitoring of a landfill site that has been certified closed by the applicable regulatory agency. Generally, we are required to maintain and monitor landfill sites for a 30-year period. These maintenance and monitoring costs are recorded as an asset retirement obligation as airspace is consumed over the life of the landfill with a corresponding increase in the landfill asset. Post-closure obligations are recorded over the life of the landfill based on estimates of the discounted cash flows associated with performing post-closure activities.

We develop our estimates of these obligations using input from our operations personnel, engineers and accountants. Our estimates are based on our interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. Absent quoted market prices, the estimate of fair value is based on the best available information, including the results of present value techniques. In many cases, we contract with third parties to fulfill our obligations for final capping, closure and post-closure. We use historical experience, professional engineering judgment and quoted and actual prices paid for similar work to determine the fair value of these obligations. We are required to recognize these obligations at market prices whether we plan to contract with third parties or perform the work ourselves. In those instances where we perform the work with internal resources, the incremental profit margin realized is recognized as a component of operating income when the work is performed.

Once we have determined the final capping, closure and post-closure costs, we inflate those costs to the expected time of payment and discount those expected future costs back to present value. During the years ended December 31, 2015, 2014 and 2013, we inflated these costs in current dollars until the expected time of payment using an inflation rate of 2.5%. We discounted these costs to present value using the credit-adjusted, risk-free rate effective at the time an obligation is incurred, consistent with the expected cash flow approach. Any changes in expectations that result in an upward revision to the estimated cash flows are treated as a new liability and discounted at the current rate while downward revisions are discounted at the historical weighted average rate of the recorded obligation. As a result, the credit-adjusted, risk-free discount rate used to calculate the present value of an obligation is specific to each individual asset retirement obligation. The weighted average rate applicable to our long-term asset retirement obligations at December 31, 2015 is approximately 6.25%. We expect to apply a credit-adjusted, risk-free discount rate of 4.50% to liabilities incurred in the first quarter of 2016.

We record the estimated fair value of final capping, closure and post-closure liabilities for our landfills based on the capacity consumed through the current period. The fair value of final capping obligations is developed based on our estimates of the airspace consumed to date for each final capping event and the expected timing of each final capping event. The fair value of closure and post-closure obligations is developed based on our estimates of the airspace consumed to date for the entire landfill and the expected timing of each closure and post-closure activity. Because these obligations are measured at estimated fair value using present value techniques, changes in the estimated cost or timing of future final capping, closure and post-closure activities could result in a material change in these liabilities, related assets and results of operations. We assess the appropriateness of the estimates used to develop our recorded balances annually, or more often if significant facts change.

Changes in inflation rates or the estimated costs, timing or extent of future final capping, closure and post-closure activities typically result in both (i) a current adjustment to the recorded liability and landfill asset and (ii) a change in liability and asset amounts to be recorded prospectively over either the remaining capacity of the related discrete final capping event or the remaining permitted and expansion airspace (as defined below) of the landfill. Any changes related to the capitalized and future cost of the landfill assets are then recognized in accordance with our amortization policy, which would generally result in amortization expense being recognized prospectively over the remaining capacity of the final capping event or the remaining permitted and expansion airspace of the landfill, as appropriate. Changes in such estimates associated with airspace that has been fully utilized result in an adjustment to the recorded liability and landfill assets with an immediate corresponding adjustment to landfill airspace amortization expense.

Interest accretion on final capping, closure and post-closure liabilities is recorded using the effective interest method and is recorded as final capping, closure and post-closure expense, which is included in “Operating” expenses within our Consolidated Statements of Operations.

Amortization of Landfill Assets — The amortizable basis of a landfill includes (i) amounts previously expended and capitalized; (ii) capitalized landfill final capping, closure and post-closure costs; (iii) projections of future purchase and development costs required to develop the landfill site to its remaining permitted and expansion capacity and (iv) projected asset retirement costs related to landfill final capping, closure and post-closure activities.

Amortization is recorded on a units-of-consumption basis, applying expense as a rate per ton. The rate per ton is calculated by dividing each component of the amortizable basis of a landfill by the number of tons needed to fill the corresponding asset’s airspace. For landfills that we do not own, but operate through operating or lease arrangements, the rate per ton is calculated based on expected capacity to be utilized over the lesser of the contractual term of the underlying agreement or the life of the landfill.

We apply the following guidelines in determining a landfill’s remaining permitted and expansion airspace:

• Remaining Permitted Airspace — Our engineers, in consultation with third-party engineering consultants and surveyors, are responsible for determining remaining permitted airspace at our landfills. The remaining permitted airspace is determined by an annual survey, which is used to compare the existing landfill topography to the expected final landfill topography.

• Expansion Airspace — We also include currently unpermitted expansion airspace in our estimate of remaining permitted and expansion airspace in certain circumstances. First, to include airspace associated with an expansion effort, we must generally expect the initial expansion permit application to be submitted within one year and the final expansion permit to be received within five years. Second, we must believe that obtaining the expansion permit is likely, considering the following criteria:

• Personnel are actively working on the expansion of an existing landfill, including efforts to obtain land use and local, state or provincial approvals;

• We have a legal right to use or obtain land to be included in the expansion plan;

• There are no significant known technical, legal, community, business, or political restrictions or similar issues that could negatively affect the success of such expansion; and

• Financial analysis has been completed based on conceptual design, and the results demonstrate that the expansion meets Company criteria for investment.

For unpermitted airspace to be initially included in our estimate of remaining permitted and expansion airspace, the expansion effort must meet all of the criteria listed above. These criteria are evaluated by our field-based engineers, accountants, managers and others to identify potential obstacles to obtaining the permits. Once the unpermitted airspace is included, our policy provides that airspace may continue to be included in remaining permitted and expansion airspace even if certain of these criteria are no longer met as long as we continue to believe we will ultimately obtain the permit, based on the facts and circumstances of a specific landfill. In these circumstances, continued inclusion must be approved through a landfill-specific review process that includes approval by our Chief Financial Officer and a review by the Audit Committee of our Board of Directors on a quarterly basis. Of the 21 landfill sites with expansions included at December 31, 2015, three landfills required the Chief Financial Officer to approve the inclusion of the unpermitted airspace. One landfill required approval by our Chief Financial Officer because of community or political opposition that could impede the expansion process. The remaining two landfills required approval because the permit application process did not meet the one- or five-year requirements.

When we include the expansion airspace in our calculations of remaining permitted and expansion airspace, we also include the projected costs for development, as well as the projected asset retirement costs related to final capping, closure and post-closure of the expansion in the amortization basis of the landfill.

Once the remaining permitted and expansion airspace is determined in cubic yards, an airspace utilization factor (“AUF”) is established to calculate the remaining permitted and expansion capacity in tons. The AUF is established using the measured density obtained from previous annual surveys and is then adjusted to account for future settlement. The amount of settlement that is forecasted will take into account several site-specific factors including current and projected mix of waste type, initial and projected waste density, estimated number of years of life remaining, depth of underlying waste, anticipated access to moisture through precipitation or recirculation of landfill leachate, and operating practices. In addition, the initial selection of the AUF is subject to a subsequent multi-level review by our engineering group, and the AUF used is reviewed on a periodic basis and revised as necessary. Our historical experience generally indicates that the impact of settlement at a landfill is greater later in the life of the landfill when the waste placed at the landfill approaches its highest point under the permit requirements.

After determining the costs and remaining permitted and expansion capacity at each of our landfills, we determine the per ton rates that will be expensed as waste is received and deposited at the landfill by dividing the costs by the corresponding number of tons. We calculate per ton amortization rates for each landfill for assets associated with each final capping event, for assets related to closure and post-closure activities and for all other costs capitalized or to be capitalized in the future. These rates per ton are updated annually, or more often, as significant facts change.

It is possible that actual results, including the amount of costs incurred, the timing of final capping, closure and post-closure activities, our airspace utilization or the success of our expansion efforts could ultimately turn out to be significantly different from our estimates and assumptions. To the extent that such estimates, or related assumptions, prove to be significantly different than actual results, lower profitability may be experienced due to higher amortization rates or higher expenses; or higher profitability may result if the opposite occurs. Most significantly, if it is determined that expansion capacity should no longer be considered in calculating the recoverability of a landfill asset, we may be required to recognize an asset impairment or incur significantly higher amortization expense. If at any time management makes the decision to abandon the expansion effort, the capitalized costs related to the expansion effort are expensed immediately.

Environmental Remediation Liabilities

Environmental Remediation Liabilities

We are subject to an array of laws and regulations relating to the protection of the environment. Under current laws and regulations, we may have liabilities for environmental damage caused by operations, or for damage caused by conditions that existed before we acquired a site. These liabilities include potentially responsible party (“PRP”) investigations, settlements, and certain legal and consultant fees, as well as costs directly associated with site investigation and clean up, such as materials, external contractor costs and incremental internal costs directly related to the remedy. We provide for expenses associated with environmental remediation obligations when such amounts are probable and can be reasonably estimated. We routinely review and evaluate sites that require remediation and determine our estimated cost for the likely remedy based on a number of estimates and assumptions.

Where it is probable that a liability has been incurred, we estimate costs required to remediate sites based on site-specific facts and circumstances. We routinely review and evaluate sites that require remediation, considering whether we were an owner, operator, transporter, or generator at the site, the amount and type of waste hauled to the site and the number of years we were associated with the site. Next, we review the same type of information with respect to other named and unnamed PRPs. Estimates of the costs for the likely remedy are then either developed using our internal resources or by third-party environmental engineers or other service providers. Internally developed estimates are based on:

• Management’s judgment and experience in remediating our own and unrelated parties’ sites;

• Information available from regulatory agencies as to costs of remediation;

• The number, financial resources and relative degree of responsibility of other PRPs who may be liable for remediation of a specific site; and

• The typical allocation of costs among PRPs, unless the actual allocation has been determined.

Estimating our degree of responsibility for remediation is inherently difficult. We recognize and accrue for an estimated remediation liability when we determine that such liability is both probable and reasonably estimable. Determining the method and ultimate cost of remediation requires that a number of assumptions be made. There can sometimes be a range of reasonable estimates of the costs associated with the likely site remediation alternatives identified in the investigation of the extent of environmental impact. In these cases, we use the amount within the range that constitutes our best estimate. If no amount within a range appears to be a better estimate than any other, we use the amount that is the low end of such range. If we used the high ends of such ranges, our aggregate potential liability would be approximately $190 million higher than the $209 million recorded in the Consolidated Financial Statements as of December 31, 2015. Our ultimate responsibility may differ materially from current estimates. It is possible that technological, regulatory or enforcement developments, the results of environmental studies, the inability to identify other PRPs, the inability of other PRPs to contribute to the settlements of such liabilities, or other factors could require us to record additional liabilities. Our ongoing review of our remediation liabilities, in light of relevant internal and external facts and circumstances, could result in revisions to our accruals that could cause upward or downward adjustments to income from operations. These adjustments could be material in any given period.

Where we believe that both the amount of a particular environmental remediation liability and the timing of the payments are fixed or reliably determinable, we inflate the cost in current dollars (by 2.5% at December 31, 2015 and 2014) until the expected time of payment and discount the cost to present value using a risk-free discount rate, which is based on the rate for U.S. Treasury bonds with a term approximating the weighted average period until settlement of the underlying obligation. We determine the risk-free discount rate and the inflation rate on an annual basis unless interim changes would significantly impact our results of operations. For remedial liabilities that have been discounted, we include interest accretion, based on the effective interest method, in “Operating” expenses in our Consolidated Statements of Operations. The following table summarizes the impacts of revisions in the risk-free discount rate applied to our environmental remediation liabilities and recovery assets during the reported periods (in millions) and the risk-free discount rate applied as of each reporting date:

	Years Ended December 31,
	2015			2014			2013
Charge (reduction) to Operating expenses	$	(2	)	$	10		$	(13	)
Risk-free discount rate applied to environmental remediation liabilities and recovery assets		2.25	%		2.00	%		3.00	%

The portion of our recorded environmental remediation liabilities that were not subject to inflation or discounting, as the amounts and timing of payments are not fixed or reliably determinable, was $52 million at December 31, 2015 and $41 million at December 31, 2014. Had we not inflated and discounted any portion of our environmental remediation liability, the amount recorded would have decreased by $3 million and $6 million at December 31, 2015 and 2014, respectively.

Property and Equipment (exclusive of landfills, discussed above)

Property and Equipment (exclusive of landfills, discussed above)

We record property and equipment at cost. Expenditures for major additions and improvements are capitalized and maintenance activities are expensed as incurred. We depreciate property and equipment over the estimated useful life of the asset using the straight-line method. We assume no salvage value for our depreciable property and equipment. When property and equipment are retired, sold or otherwise disposed of, the cost and accumulated depreciation are removed from our accounts and any resulting gain or loss is included in results of operations as an offset or increase to operating expense for the period.

The estimated useful lives for significant property and equipment categories are as follows (in years):

	Useful Lives
Vehicles — excluding rail haul cars		3 to 10
Vehicles — rail haul cars		10 to 20
Machinery and equipment — including containers		3 to 30
Buildings and improvements		5 to 40
Furniture, fixtures and office equipment		3 to 10

We include capitalized costs associated with developing or obtaining internal-use software within furniture, fixtures and office equipment. These costs include direct external costs of materials and services used in developing or obtaining the software and internal costs for employees directly associated with the software development project.

Leases

Leases

We lease property and equipment in the ordinary course of our business. Our most significant lease obligations are for property and equipment specific to our industry, including real property operated as a landfill or transfer station. Our leases have varying terms. Some may include renewal or purchase options, escalation clauses, restrictions, penalties or other obligations that we consider in determining minimum lease payments. The leases are classified as either operating leases or capital leases, as appropriate.

Operating Leases (excluding landfills discussed below) — The majority of our leases are operating leases. This classification generally can be attributed to either (i) relatively low fixed minimum lease payments as a result of real property lease obligations that vary based on the volume of waste we receive or process or (ii) minimum lease terms that are much shorter than the assets’ economic useful lives. Management expects that in the normal course of business our operating leases will be renewed, replaced by other leases, or replaced with fixed asset expenditures. Our rent expense during each of the last three years and our future minimum operating lease payments for each of the next five years for which we are contractually obligated as of December 31, 2015 are disclosed in Note 11.

Capital Leases (excluding landfills discussed below) — Assets under capital leases are capitalized using interest rates determined at the inception of each lease and are amortized over either the useful life of the asset or the lease term, as appropriate, on a straight-line basis. The present value of the related lease payments is recorded as a debt obligation. Our future minimum annual capital lease payments are included in our total future debt obligations as disclosed in Note 7.

Landfill Leases — From an operating perspective, landfills that we lease are similar to landfills we own because generally we own the landfill’s operating permit and will operate the landfill for the entire lease term, which in many cases is the life of the landfill. As a result, our landfill leases are generally capital leases. The most significant portion of our rental obligations for landfill leases is contingent upon operating factors such as disposal volumes and often there are no contractual minimum rental obligations. Contingent rental obligations are expensed as incurred. For landfill capital leases that provide for minimum contractual rental obligations, we record the present value of the minimum obligation as part of the landfill asset, which is amortized on a units-of-consumption basis over the shorter of the lease term or the life of the landfill.

Acquisitions

Acquisitions

We generally recognize assets acquired and liabilities assumed in business combinations, including contingent assets and liabilities, based on fair value estimates as of the date of acquisition.

Contingent Consideration — In certain acquisitions, we agree to pay additional amounts to sellers contingent upon achievement by the acquired businesses of certain negotiated goals, such as targeted revenue levels, targeted disposal volumes or the issuance of permits for expanded landfill airspace. We have recognized liabilities for these contingent obligations based on their estimated fair value at the date of acquisition with any differences between the acquisition-date fair value and the ultimate settlement of the obligations being recognized as an adjustment to income from operations.

Acquired Assets and Assumed Liabilities — Assets and liabilities arising from contingencies such as pre-acquisition environmental matters and litigation are recognized at their acquisition-date fair value when their respective fair values can be determined. If the fair values of such contingencies cannot be determined, they are recognized at the acquisition date if the contingencies are probable and an amount can be reasonably estimated.

Acquisition-date fair value estimates are revised as necessary and accounted for as an adjustment to income from operations if, and when, additional information regarding these contingencies becomes available to further define and quantify assets acquired and liabilities assumed. All acquisition-related transaction costs have been expensed as incurred.

Goodwill and Other Intangible Assets

Goodwill and Other Intangible Assets

Goodwill is the excess of our purchase cost over the fair value of the net assets of acquired businesses. We do not amortize goodwill, but as discussed in the Asset Impairments section below, we assess our goodwill for impairment at least annually.

Other intangible assets consist primarily of customer and supplier relationships, covenants not-to-compete, licenses, permits (other than landfill permits, as all landfill-related intangible assets are combined with landfill tangible assets and amortized using our landfill amortization policy), and other contracts. Other intangible assets are recorded at acquisition date fair value and are generally amortized using either a 150% declining balance approach or a straight-line basis as we determine appropriate. Customer and supplier relationships are typically amortized over a term ranging between 10 and 15 years. Covenants not-to-compete are amortized over the term of the non-compete covenant, which is generally two to five years. Licenses, permits and other contracts are amortized over the definitive terms of the related agreements. If the underlying agreement does not contain definitive terms and the useful life is determined to be indefinite, the asset is not amortized.

Asset Impairments

Asset Impairments

We monitor the carrying value of our long-lived assets for potential impairment on an ongoing basis and test the recoverability of such assets using significant unobservable (“Level 3”) inputs whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. These events or changes in circumstances, including management decisions pertaining to such assets, are referred to as impairment indicators. If an impairment indicator occurs, we perform a test of recoverability by comparing the carrying value of the asset or asset group to its undiscounted expected future cash flows. If cash flows cannot be separately and independently identified for a single asset, we will determine whether an impairment has occurred for the group of assets for which we can identify the projected cash flows. If the carrying values are in excess of undiscounted expected future cash flows, we measure any impairment by comparing the fair value of the asset or asset group to its carrying value. Fair value is generally determined by considering (i) internally developed discounted projected cash flow analysis of the asset or asset group; (ii) actual third-party valuations and/or (iii) information available regarding the current market for similar assets. If the fair value of an asset or asset group is determined to be less than the carrying amount of the asset or asset group, an impairment in the amount of the difference is recorded in the period that the impairment indicator occurs and is included in the “(Income) expense from divestitures, asset impairments (other than goodwill) and unusual items” line item in our Consolidated Statement of Operations. Estimating future cash flows requires significant judgment and projections may vary from the cash flows eventually realized, which could impact our ability to accurately assess whether an asset has been impaired.

There are additional considerations for impairments of landfills, goodwill and other indefinite-lived intangible assets, as described below.

Landfills — The assessment of impairment indicators and the recoverability of our capitalized costs associated with landfills and related expansion projects require significant judgment due to the unique nature of the waste industry, the highly regulated permitting process and the sensitive estimates involved. During the review of a landfill expansion application, a regulator may initially deny the expansion application although the expansion permit is ultimately granted. In addition, management may periodically divert waste from one landfill to another to conserve remaining permitted landfill airspace, or a landfill may be required to cease accepting waste, prior to receipt of the expansion permit. However, such events occur in the ordinary course of business in the waste industry and do not necessarily result in impairment of our landfill assets because, after consideration of all facts, such events may not affect our belief that we will ultimately obtain the expansion permit. As a result, our tests of recoverability, which generally make use of a probability-weighted cash flow estimation approach, may indicate that no impairment loss should be recorded. During the year ended December 31, 2013, we recognized $262 million of charges to impair certain of our landfills, primarily as a result of our consideration of management’s decision in the fourth quarter of 2013 not to actively pursue expansion and/or development of such landfills. These charges were primarily associated with two landfills in our Eastern Canada Area, which are no longer accepting waste. We had previously concluded that receipt of permits for these landfills was probable. However, in connection with our asset rationalization and capital allocation analysis, which was influenced, in part, by our acquisition of RCI Environnement, Inc. (“RCI”), we determined that the future costs to construct these landfills could be avoided as we are able to allocate disposal that would have gone to these landfills to other facilities and not materially impact operations. As a result of management’s decision, we determined that the carrying values of landfill assets were no longer able to be recovered by the undiscounted cash flows attributable to these assets. As such, we wrote their carrying values down to their estimated fair values using a market approach considering the highest and best use of the assets.

Goodwill — At least annually, and more frequently if warranted, we assess our goodwill for impairment using Level 3 inputs.

We assess whether a goodwill impairment exists using both qualitative and quantitative assessments. Our qualitative assessment involves determining whether events or circumstances exist that indicate it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. If based on this qualitative assessment we determine it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, we will not perform a quantitative assessment.

If the qualitative assessment indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount or if we elect not to perform a qualitative assessment, we perform a quantitative assessment, or two-step impairment test, to determine whether a goodwill impairment exists at the reporting unit. The first step in our quantitative assessment identifies potential impairments by comparing the estimated fair value of the reporting unit to its carrying value, including goodwill. If the carrying value exceeds estimated fair value, there is an indication of potential impairment and the second step is performed to measure the amount of impairment. Fair value is typically estimated using a combination of the income approach and market approach or only an income approach when applicable. The income approach is based on the long-term projected future cash flows of the reporting units. We discount the estimated cash flows to present value using a weighted average cost of capital that considers factors such as market assumptions, the timing of the cash flows and the risks inherent in those cash flows. We believe that this approach is appropriate because it provides a fair value estimate based upon the reporting units’ expected long-term performance considering the economic and market conditions that generally affect our business. The market approach estimates fair value by measuring the aggregate market value of publicly-traded companies with similar characteristics to our business as a multiple of their reported cash flows. We then apply that multiple to the reporting units’ cash flows to estimate their fair values. We believe that this approach is appropriate because it provides a fair value estimate using valuation inputs from entities with operations and economic characteristics comparable to our reporting units.

Fair value computed by these two methods is arrived at using a number of factors, including projected future operating results, economic projections, anticipated future cash flows, comparable marketplace data and the cost of capital. There are inherent uncertainties related to these factors and to our judgment in applying them to this analysis. However, we believe that these two methods provide a reasonable approach to estimating the fair value of our reporting units.

During our annual 2013 impairment test of our goodwill balances we determined the fair value of our Wheelabrator business had declined and the associated goodwill was impaired. As a result, we recognized an impairment charge of $483 million, which had no related tax benefit. We estimated the implied fair value of our Wheelabrator reporting unit goodwill using a combination of income and market approaches. Because the annual impairment test indicated that Wheelabrator’s carrying value exceeded its estimated fair value, we performed the “step two” analysis. In the “step two” analysis, the fair values of all assets and liabilities were estimated, including tangible assets, power contracts, customer relationships and trade name for the purpose of deriving an estimate of the implied fair value of goodwill. The implied fair value of goodwill was then compared to the carrying amount of goodwill to determine the amount of the impairment. The factors contributing to the $483 million goodwill impairment charge principally related to the continued challenging business environment in areas of the country in which Wheelabrator operated, characterized by lower available disposal volumes (which impact disposal rates and overall disposal revenue, as well as the amount of electricity Wheelabrator was able to generate), lower electricity pricing due to the pricing pressure created by availability of natural gas and increased operating costs as Wheelabrator’s facilities aged. These factors caused us to lower prior assumptions for electricity and disposal revenue, and increase assumed operating costs. Additionally, the discount factor previously utilized in the income approach in 2013 increased mainly due to increases in interest rates. In 2013, we also incurred $10 million of charges to impair goodwill associated with our Puerto Rico operations. In 2014, we recognized $10 million of goodwill impairment charges associated with our recycling operations.

Refer to Note 13 for information related to impairments recognized during the reported periods.

Indefinite-Lived Intangible Assets Other Than Goodwill — At least annually, and more frequently if warranted, we assess indefinite-lived intangible assets other than goodwill for impairment.

When performing the impairment test for indefinite-lived intangible assets, we generally first conduct a qualitative analysis to determine whether we believe it is more likely than not that an asset has been impaired. If we believe an impairment has occurred, we then evaluate for impairment by comparing the estimated fair value of assets to the carrying value. An impairment charge is recognized if the asset’s estimated fair value is less than its carrying value.

Fair value is typically estimated using an income approach. The income approach is based on the long-term projected future cash flows. We discount the estimated cash flows to present value using a weighted average cost of capital that considers factors such as market assumptions, the timing of the cash flows and the risks inherent in those cash flows. We believe that this approach is appropriate because it provides a fair value estimate based upon the expected long-term performance considering the economic and market conditions that generally affect our business.

Fair value computed by this method is arrived at using a number of factors, including projected future operating results, economic projections, anticipated future cash flows, comparable marketplace data and the cost of capital. There are inherent uncertainties related to these factors and to our judgment in applying them to this analysis. However, we believe that this method provides a reasonable approach to estimating the fair value of the reporting units.

Restricted Trust and Escrow Accounts

Restricted Trust and Escrow Accounts

Our restricted trust and escrow accounts consist principally of funds deposited for purposes of settling landfill final capping, closure, post-closure and environmental remediation obligations. At several of our landfills, we provide financial assurance by depositing cash into restricted trust funds or escrow accounts for purposes of settling final capping, closure, post-closure and environmental remediation obligations. Balances maintained in these trust funds and escrow accounts will fluctuate based on (i) changes in statutory requirements; (ii) future deposits made to comply with contractual arrangements; (iii) the ongoing use of funds for qualifying final capping, closure, post-closure and environmental remediation activities; (iv) acquisitions or divestitures of landfills and (v) changes in the fair value of the financial instruments held in the trust fund or escrow accounts. As of December 31, 2015 and 2014, we had $105 million and $171 million, respectively, of restricted trust and escrow accounts, which are primarily included in “Other assets” in our Consolidated Balance Sheets. See Note 20 for additional discussion related to restricted trust and escrow accounts.

Investments in Unconsolidated Entities

Investments in Unconsolidated Entities

Investments in unconsolidated entities over which the Company has significant influence are accounted for under the equity method of accounting. Investments in entities in which the Company does not have the ability to exert significant influence over the investees’ operating and financing activities are accounted for under the cost method of accounting. The following table summarizes our equity and cost method investments as of December 31 (in millions):

	2015		2014
Equity investments	$	186	$	228
Cost investments		174		180
Investments in unconsolidated entities	$	360	$	408

We monitor and assess the carrying value of our investments throughout the year for potential impairment and write them down to their fair value when other-than-temporary declines exist. Fair value is generally based on (i) other third-party investors’ recent transactions in the securities; (ii) other information available regarding the current market for similar assets and/or (iii) a market or income approach as deemed appropriate.

Foreign Currency

Foreign Currency

We have operations in Canada as well as a cost center in India and investments in Hong Kong. Local currencies generally are considered the functional currencies of our operations and investments outside the United States. The assets and liabilities of our foreign operations are translated to U.S. dollars using the exchange rate at the balance sheet date. Revenues and expenses are translated to U.S. dollars using the average exchange rate during the period. The resulting translation difference is reflected as a component of comprehensive income.

Derivative Financial Instruments

Derivative Financial Instruments

We primarily use derivative financial instruments to manage our risk associated with fluctuations in interest rates and foreign currency exchange rates. In prior years, we used interest rate swaps to maintain a strategic portion of our long-term debt obligations at variable, market-driven interest rates or in anticipation of planned senior note issuances to effectively lock in a fixed interest rate for those anticipated issuances. We use foreign currency exchange rate derivatives to hedge our exposure to fluctuations in exchange rates for anticipated intercompany cash transactions between Waste Management Holdings, Inc., a wholly-owned subsidiary (“WM Holdings”), and its Canadian subsidiaries. Prior to the sale of our Wheelabrator business in December 2014, we used electricity commodity derivatives to mitigate the variability in our revenues and cash flows caused by fluctuations in the market prices for electricity. The financial statement impacts of our derivatives are discussed in Notes 8 and 14.

We obtain current valuations of our foreign currency hedging instruments from third-party pricing models. The estimated fair values of derivatives used to hedge risks fluctuate over time and should be viewed in relation to the underlying hedged transaction and the overall management of our exposure to fluctuations in the underlying risks. The fair value of derivatives is included in other current assets, other long-term assets, current accrued liabilities or other long-term liabilities, as appropriate. Any ineffectiveness present in either fair value or cash flow hedges is recognized immediately in earnings without offset. There was no significant ineffectiveness in 2015, 2014 or 2013.

• Foreign Currency Derivatives — Our foreign currency derivatives have been designated as cash flow hedges for accounting purposes, which results in the unrealized changes in the fair value of the derivative instruments being recorded in “Accumulated other comprehensive income” within the equity section of our Consolidated Balance Sheets. The associated balance in other comprehensive income is reclassified to earnings as the hedged cash flows affect earnings. In each of the periods presented, these derivatives have effectively mitigated the impacts of the hedged transactions, resulting in immaterial impacts to our results of operations for the periods presented.

• Interest Rate Derivatives — Our previously outstanding interest rate swaps associated with outstanding fixed-rate senior notes had been designated as fair value hedges for accounting purposes. Accordingly, derivative assets were accounted for as an increase in the carrying value of our underlying debt obligations and derivative liabilities were accounted for as a decrease in the carrying value of our underlying debt instruments. These fair value adjustments are deferred and recognized as an adjustment to interest expense over the remaining term of the hedged instruments. Treasury locks and forward-starting swaps executed in prior years were designated as cash flow hedges for accounting purposes. The fair value of these derivative instruments were recorded in “Accumulated other comprehensive income” within the equity section of our Consolidated Balance Sheets. The associated balance in other comprehensive income is reclassified to earnings as the hedged cash flows occur.

Insured and Self-Insured Claims

Insured and Self-Insured Claims

We have retained a significant portion of the risks related to our health and welfare, automobile, general liability and workers’ compensation claims programs. The exposure for unpaid claims and associated expenses, including incurred but not reported losses, generally is estimated with the assistance of external actuaries and by factoring in pending claims and historical trends and data. The gross estimated liability associated with settling unpaid claims is included in “Accrued liabilities” in our Consolidated Balance Sheets if expected to be settled within one year, or otherwise is included in long-term “Other liabilities.” Estimated insurance recoveries related to recorded liabilities are reflected as current “Other receivables” or long-term “Other assets” in our Consolidated Balance Sheets when we believe that the receipt of such amounts is probable.

Revenue Recognition

Revenue Recognition

Our revenues are generated from the fees we charge for waste collection, transfer, disposal and recycling and resource recovery services; from the sale of electricity and landfill gas, which are byproducts of our landfill operations; and from the sale of recyclable commodities, oil and gas and organic lawn and garden products. The fees charged for our services are generally defined in our service agreements and vary based on contract-specific terms such as frequency of service, weight, volume and the general market factors influencing a region’s rates. The fees we charge for our services generally include fuel surcharges, which are intended to pass through to customers increased direct and indirect costs incurred because of changes in market prices for fuel. We generally recognize revenue as services are performed or products are delivered. For example, revenue typically is recognized as waste is collected, tons are received at our landfills or transfer stations, or recycling commodities are delivered.

Tangible product revenues primarily include the sale of recyclable commodities at our material recovery facilities and through our recycling brokerage services and, to a lesser extent, sales of oil and gas, metals and organic lawn and garden products.

We bill for certain services prior to performance. Such services include, among others, certain residential contracts that are billed on a quarterly basis and equipment rentals. These advance billings are included in deferred revenues and recognized as revenue in the period service is provided.

Capitalized Interest

Capitalized Interest

We capitalize interest on certain projects under development, including internal-use software and landfill expansion projects, and on certain assets under construction, including operating landfills and landfill gas-to-energy projects. During 2015, 2014 and 2013, total interest costs were $407 million, $487 million and $500 million, respectively, of which $16 million was capitalized in 2015, $16 million was capitalized in 2014 and $19 million was capitalized in 2013. In 2015, 2014 and 2013, interest was capitalized primarily for landfill construction costs.

Income Taxes

Income Taxes

The Company is subject to income tax in the U.S. and Canada. Current tax obligations associated with our provision for income taxes are reflected in the accompanying Consolidated Balance Sheets as a component of “Accrued liabilities” and the deferred tax obligations are reflected in “Deferred income taxes.”

Deferred income taxes are based on the difference between the financial reporting and tax basis of assets and liabilities. The deferred income tax provision represents the change during the reporting period in the deferred tax assets and deferred tax liabilities, net of the effect of acquisitions and dispositions. Deferred tax assets include tax loss and credit carry-forwards and are reduced by a valuation allowance if, based on available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Significant judgment is required in assessing the timing and amounts of deductible and taxable items. We establish reserves for uncertain tax positions when, despite our belief that our tax return positions are fully supportable, we believe that certain positions may be challenged and potentially disallowed. When facts and circumstances change, we adjust these reserves through our provision for income taxes.

Should interest and penalties be assessed by taxing authorities on any underpayment of income tax, such amounts would be accrued and classified as a component of income tax expense in our Consolidated Statements of Operations.

Contingent Liabilities

Contingent Liabilities

We estimate the amount of potential exposure we may have with respect to claims, assessments and litigation in accordance with U.S. Generally Accepted Accounting Principles. We are party to pending or threatened legal proceedings covering a wide range of matters in various jurisdictions. It is difficult to predict the outcome of litigation, as it is subject to many uncertainties. Additionally, it is not always possible for management to make a meaningful estimate of the potential loss or range of loss associated with such contingencies. See Note 11 for discussion of our commitments and contingencies.

Supplemental Cash Flow Information

Supplemental Cash Flow Information

	Years Ended December 31,
Cash paid during the year (in millions):	2015		2014		2013
Interest, net of capitalized interest and periodic settlements from interest rate swap agreements	$	384	$	461	$	478
Income taxes		419		758		511

For the year ended December 31, 2015, non-cash investing and financing activities included $262 million of tax-exempt bond refundings and reissuances as discussed further in Note 7. For the year ended December 31, 2013, non-cash investing and financing activities included proceeds from tax-exempt borrowings, net of principal payments made directly from trust funds, of $99 million. During 2014 we did not have any significant non-cash investing and financing activities. Non-cash investing and financing activities are generally excluded from the Consolidated Statements of Cash Flows.