Variable Interest Entities	12 Months Ended
Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	20. Variable Interest Entities Following is a description of our financial interests in both consolidated and unconsolidated variable interest entities that we consider significant: *Unconsolidated Variable Interest Entities* Low-Income Housing Properties and Refined Coal Facility Investments — We have significant financial interests in entities established to invest in and manage low-income housing properties and a refined coal facility. We support the operations of these entities in exchange for a pro-rata share of the tax credits they generate. We do not consolidate these entities as we have determined we are not the primary beneficiary of these entities as we do not have the power to individually direct the activities of these entities. Accordingly, we account for these investments under the equity method of accounting. As of December 31, 2016 and 2015, our aggregate investment balance in these two entities was $84 million and $110 million, respectively. The debt balance related to our investment in low-income housing properties was $57 million and $80 million at December 31, 2016 and 2015, respectively. Additional information related to these investments is discussed in Note 9. Trust Funds 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. 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 do not consolidate these trust funds as we are not the primary beneficiary 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. Our interests in these trusts 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 as of December 31, 2016 and 2015. As the party with primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities for these trust funds, we are exposed to risk of loss as a result of potential changes in the fair value of the assets of the trust. We currently expect the trust funds to continue to meet the statutory requirements for which they were established. *Consolidated Variable Interest Entities* Trust Funds for Final Capping, Closure, Post-Closure or Environmental Remediation Obligations — We also have significant financial interests in trust funds that were created to settle certain of our final capping, closure, post-closure or environmental remediation obligations of which we are the sole beneficiary of these restricted balances. We have determined that these trust funds are variable interest entities and we consolidate these trust funds as we are the primary beneficiary. We account for the trust funds for which we are the sole beneficiary as long-term “Other assets” in our Consolidated Balance Sheets. 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 (loss).” These trusts had a fair value of $95 million and $94 million at December 31, 2016 and 2015, respectively. We are also the party with primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities for these trust funds and we are exposed to risk of loss as a result of potential changes in the fair value of the assets of the trust. We currently expect the trust funds to continue to meet the statutory requirements for which they were established. 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 year ended December 31, 2014 we recognized a reduction in earnings of $39 million for Hancock’s and CIT’s noncontrolling interests in the LLCs’ earnings, which was 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. The LLCs were then subsequently sold as part of the divestiture of our Wheelabrator business. See Note 19 for further discussion of the sale of our Wheelabrator business.

20. Variable Interest Entities

Following is a description of our financial interests in both consolidated and unconsolidated variable interest entities that we consider significant:

Unconsolidated Variable Interest Entities

Low-Income Housing Properties and Refined Coal Facility Investments — We have significant financial interests in entities established to invest in and manage low-income housing properties and a refined coal facility. We support the operations of these entities in exchange for a pro-rata share of the tax credits they generate. We do not consolidate these entities as we have determined we are not the primary beneficiary of these entities as we do not have the power to individually direct the activities of these entities. Accordingly, we account for these investments under the equity method of accounting. As of December 31, 2016 and 2015, our aggregate investment balance in these two entities was $84 million and $110 million, respectively. The debt balance related to our investment in low-income housing properties was $57 million and $80 million at December 31, 2016 and 2015, respectively. Additional information related to these investments is discussed in Note 9.

Trust Funds 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. 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 do not consolidate these trust funds as we are not the primary beneficiary 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. Our interests in these trusts 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 as of December 31, 2016 and 2015.

As the party with primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities for these trust funds, we are exposed to risk of loss as a result of potential changes in the fair value of the assets of the trust. We currently expect the trust funds to continue to meet the statutory requirements for which they were established.

Consolidated Variable Interest Entities

Trust Funds for Final Capping, Closure, Post-Closure or Environmental Remediation Obligations — We also have significant financial interests in trust funds that were created to settle certain of our final capping, closure, post-closure or environmental remediation obligations of which we are the sole beneficiary of these restricted balances. We have determined that these trust funds are variable interest entities and we consolidate these trust funds as we are the primary beneficiary. We account for the trust funds for which we are the sole beneficiary as long-term “Other assets” in our Consolidated Balance Sheets. 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 (loss).” These trusts had a fair value of $95 million and $94 million at December 31, 2016 and 2015, respectively.

We are also the party with primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities for these trust funds and we are exposed to risk of loss as a result of potential changes in the fair value of the assets of the trust. We currently expect the trust funds to continue to meet the statutory requirements for which they were established.

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 year ended December 31, 2014 we recognized a reduction in earnings of $39 million for Hancock’s and CIT’s noncontrolling interests in the LLCs’ earnings, which was 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. The LLCs were then subsequently sold as part of the divestiture of our Wheelabrator business. See Note 19 for further discussion of the sale of our Wheelabrator business.