Variable Interest Entities	12 Months Ended
Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	20. Variable Interest Entities Following is a description of our financial interests in variable interest entities that we consider significant, including (i) those for which we have determined that we are the primary beneficiary of the entity and, therefore, have consolidated the entities into our financial statements; (ii) those that represent a significant interest in an unconsolidated entity and (iii) trusts for final capping, closure, post-closure or environmental remediation obligations for both consolidated and unconsolidated variable interest entities. *Consolidated Variable Interest Entities* Waste-to-Energy LLCs — In June 2000, two limited liability companies were established to purchase interests in existing leveraged lease financings at three waste-to-energy facilities that we leased, operated and maintained. We initially owned a 0.5% interest in one of the LLCs (“LLC I”) and a 0.25% interest in the second LLC (“LLC II”). John Hancock Life Insurance Company (“Hancock”) owned 99.5% of LLC I and 99.75% of LLC II was owned by LLC I and the CIT Group (“CIT”). We determined that we were the primary beneficiary of the LLCs and consolidated these entities in our Consolidated Financial Statements because (i) all of the equity owners of the LLCs were considered related parties for purposes of applying this accounting guidance; (ii) the equity owners shared power over the significant activities of the LLCs and (iii) we were the entity within the related party group whose activities were most closely associated with the LLCs. During the years ended December 31, 2014 and 2013 we recognized reductions in earnings of $39 million and $43 million, respectively, for Hancock’s and CIT’s noncontrolling interests in the LLCs’ earnings, which are included in our consolidated net income. The LLCs’ earnings related to the rental income generated from leasing the facilities to our subsidiaries, reduced by depreciation expense. The LLCs’ rental income was eliminated in WM’s consolidation. In December 2014, we purchased the noncontrolling interests in the LLCs from Hancock and CIT in anticipation of our sale of our Wheelabrator business. The LLCs were then subsequently sold as part of the divestment. See Note 19 for further discussion of the sale of our Wheelabrator business. *Significant Unconsolidated Variable Interest Entities* Investment in Refined Coal Facility — In 2011, we acquired a noncontrolling interest in a limited liability company established to invest in and manage a refined coal facility. Along with the other equity investor, we support the operations of the entity in exchange for a pro-rata share of the tax credits it generates. Our initial consideration for this investment consisted of a cash payment of $48 million. At December 31, 2015 and 2014, our investment balance was $29 million and $32 million, respectively, representing our current maximum pre-tax exposure to loss. Under the terms and conditions of the transaction, we do not believe that we have any material exposure to loss. Required capital contributions commenced in 2013 and will continue through the expiration of the tax credits under Section 45 of the Internal Revenue Code, which occurs at the end of 2019. We are only obligated to make future contributions to the extent tax credits are generated. We determined that we are not the primary beneficiary of this entity as we do not have the power to individually direct the entity’s activities. Accordingly, we account for this investment under the equity method of accounting and do not consolidate the entity. Additional information related to this investment is discussed in Note 9. Investment in Low-Income Housing Properties — In 2010, we acquired a noncontrolling interest in a limited liability company established to invest in and manage low-income housing properties. We support the operations of the entity in exchange for a pro-rata share of the tax credits it generates. Our target return on the investment is guaranteed and, therefore, we do not believe that we have any material exposure to loss. Our consideration for this investment totaled $221 million, which was comprised of a $215 million note payable and an initial cash payment of $6 million. At December 31, 2015 and 2014, our investment balance was $81 million and $104 million, respectively, and our debt balance was $80 million and $104 million, respectively. We determined that we are not the primary beneficiary of this entity as we do not have the power to individually direct the entity’s activities. Accordingly, we account for this investment under the equity method of accounting and do not consolidate the entity. Additional information related to this investment is discussed in Note 9. *Trusts for Final Capping, Closure, Post-Closure or Environmental Remediation Obligations* We have significant financial interests in trust funds that were created to settle certain of our final capping, closure, post-closure or environmental remediation obligations. Generally, we are the sole beneficiary of these restricted balances; however, certain of the funds have been established for the benefit of both the Company and the host community in which we operate. We have determined that these trust funds are variable interest entities; however, we are not the primary beneficiary of certain of these entities because either (i) we do not have the power to direct the significant activities of the trusts or (ii) power over the trusts’ significant activities is shared. We account for the trusts for which we are the sole beneficiary as long-term “Other assets” in our Consolidated Balance Sheet. We reflect our interests in the unrealized gains and losses on available-for-sale securities held by these trusts as a component of “Accumulated other comprehensive income.” These trusts had a fair value of $94 million at December 31, 2015 and $129 million at December 31, 2014. The decline in these balances can be attributed to our decision to work with various beneficiaries to release these funds and secure the obligations with alternate assurance instruments. Our interests in the trusts that have been established for the benefit of both the Company and the host community in which we operate are accounted for as investments in unconsolidated entities and receivables. These amounts are recorded in “Other receivables,” “Investments in unconsolidated entities” and long-term “Other assets” in our Consolidated Balance Sheets, as appropriate. Our investments and receivables related to these trusts had an aggregate carrying value of $93 million and $113 million as of December 31, 2015 and December 31, 2014, respectively. As the party with primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities, we are exposed to risk of loss as a result of potential changes in the fair value of the assets of the trust. The fair value of trust assets can fluctuate due to (i) changes in the market value of the investments held by the trusts and (ii) credit risk associated with trust receivables. Although we are exposed to changes in the fair value of the trust assets, we currently expect the trust funds to continue to meet the statutory requirements for which they were established.

20. Variable Interest Entities

Following is a description of our financial interests in variable interest entities that we consider significant, including (i) those for which we have determined that we are the primary beneficiary of the entity and, therefore, have consolidated the entities into our financial statements; (ii) those that represent a significant interest in an unconsolidated entity and (iii) trusts for final capping, closure, post-closure or environmental remediation obligations for both consolidated and unconsolidated variable interest entities.

Consolidated Variable Interest Entities

Waste-to-Energy LLCs — In June 2000, two limited liability companies were established to purchase interests in existing leveraged lease financings at three waste-to-energy facilities that we leased, operated and maintained. We initially owned a 0.5% interest in one of the LLCs (“LLC I”) and a 0.25% interest in the second LLC (“LLC II”). John Hancock Life Insurance Company (“Hancock”) owned 99.5% of LLC I and 99.75% of LLC II was owned by LLC I and the CIT Group (“CIT”). We determined that we were the primary beneficiary of the LLCs and consolidated these entities in our Consolidated Financial Statements because (i) all of the equity owners of the LLCs were considered related parties for purposes of applying this accounting guidance; (ii) the equity owners shared power over the significant activities of the LLCs and (iii) we were the entity within the related party group whose activities were most closely associated with the LLCs. During the years ended December 31, 2014 and 2013 we recognized reductions in earnings of $39 million and $43 million, respectively, for Hancock’s and CIT’s noncontrolling interests in the LLCs’ earnings, which are included in our consolidated net income. The LLCs’ earnings related to the rental income generated from leasing the facilities to our subsidiaries, reduced by depreciation expense. The LLCs’ rental income was eliminated in WM’s consolidation.

In December 2014, we purchased the noncontrolling interests in the LLCs from Hancock and CIT in anticipation of our sale of our Wheelabrator business. The LLCs were then subsequently sold as part of the divestment. See Note 19 for further discussion of the sale of our Wheelabrator business.

Significant Unconsolidated Variable Interest Entities

Investment in Refined Coal Facility — In 2011, we acquired a noncontrolling interest in a limited liability company established to invest in and manage a refined coal facility. Along with the other equity investor, we support the operations of the entity in exchange for a pro-rata share of the tax credits it generates. Our initial consideration for this investment consisted of a cash payment of $48 million. At December 31, 2015 and 2014, our investment balance was $29 million and $32 million, respectively, representing our current maximum pre-tax exposure to loss. Under the terms and conditions of the transaction, we do not believe that we have any material exposure to loss. Required capital contributions commenced in 2013 and will continue through the expiration of the tax credits under Section 45 of the Internal Revenue Code, which occurs at the end of 2019. We are only obligated to make future contributions to the extent tax credits are generated. We determined that we are not the primary beneficiary of this entity as we do not have the power to individually direct the entity’s activities. Accordingly, we account for this investment under the equity method of accounting and do not consolidate the entity. Additional information related to this investment is discussed in Note 9.

Investment in Low-Income Housing Properties — In 2010, we acquired a noncontrolling interest in a limited liability company established to invest in and manage low-income housing properties. We support the operations of the entity in exchange for a pro-rata share of the tax credits it generates. Our target return on the investment is guaranteed and, therefore, we do not believe that we have any material exposure to loss. Our consideration for this investment totaled $221 million, which was comprised of a $215 million note payable and an initial cash payment of $6 million. At December 31, 2015 and 2014, our investment balance was $81 million and $104 million, respectively, and our debt balance was $80 million and $104 million, respectively. We determined that we are not the primary beneficiary of this entity as we do not have the power to individually direct the entity’s activities. Accordingly, we account for this investment under the equity method of accounting and do not consolidate the entity. Additional information related to this investment is discussed in Note 9.

Trusts for Final Capping, Closure, Post-Closure or Environmental Remediation Obligations

We have significant financial interests in trust funds that were created to settle certain of our final capping, closure, post-closure or environmental remediation obligations. Generally, we are the sole beneficiary of these restricted balances; however, certain of the funds have been established for the benefit of both the Company and the host community in which we operate. We have determined that these trust funds are variable interest entities; however, we are not the primary beneficiary of certain of these entities because either (i) we do not have the power to direct the significant activities of the trusts or (ii) power over the trusts’ significant activities is shared.

We account for the trusts for which we are the sole beneficiary as long-term “Other assets” in our Consolidated Balance Sheet. We reflect our interests in the unrealized gains and losses on available-for-sale securities held by these trusts as a component of “Accumulated other comprehensive income.” These trusts had a fair value of $94 million at December 31, 2015 and $129 million at December 31, 2014. The decline in these balances can be attributed to our decision to work with various beneficiaries to release these funds and secure the obligations with alternate assurance instruments. Our interests in the trusts that have been established for the benefit of both the Company and the host community in which we operate are accounted for as investments in unconsolidated entities and receivables. These amounts are recorded in “Other receivables,” “Investments in unconsolidated entities” and long-term “Other assets” in our Consolidated Balance Sheets, as appropriate. Our investments and receivables related to these trusts had an aggregate carrying value of $93 million and $113 million as of December 31, 2015 and December 31, 2014, respectively.

As the party with primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities, we are exposed to risk of loss as a result of potential changes in the fair value of the assets of the trust. The fair value of trust assets can fluctuate due to (i) changes in the market value of the investments held by the trusts and (ii) credit risk associated with trust receivables. Although we are exposed to changes in the fair value of the trust assets, we currently expect the trust funds to continue to meet the statutory requirements for which they were established.