Commitments and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended			60 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Loss Contingencies [Line Items]
Loss Contingency Accrual	$ 18	$ 11		$ 18
Other Commitments	458			458
Letters of credit [Member]
Loss Contingencies [Line Items]
Other Commitments	70			70
Surety Bonds [Member]
Loss Contingencies [Line Items]
Other Commitments	196			196
Commitments Expiring Less Than One Year [Member]
Loss Contingencies [Line Items]
Other Commitments	90			90
Commitments Expiring Less Than One Year [Member] | Letters of credit [Member]
Loss Contingencies [Line Items]
Other Commitment, Due in Next Twelve Months	70			70
Commitments Expiring Less Than One Year [Member] | Surety Bonds [Member]
Loss Contingencies [Line Items]
Other Commitment, Due in Next Twelve Months	0			0
Commitments Expiring More Than One Year [Member]
Loss Contingencies [Line Items]
Other Commitments	368			368
Commitments Expiring More Than One Year [Member] | Letters of credit [Member]
Loss Contingencies [Line Items]
Other Commitment, Due after One Year	0			0
Commitments Expiring More Than One Year [Member] | Surety Bonds [Member]
Loss Contingencies [Line Items]
Other Commitment, Due after One Year	196			196
NYC Waste Contract [Member]
Loss Contingencies [Line Items]
Estimated Capital Expenditures For Project	114
Capital Invested In Project	0	3	$ 31	115
Capital Invested In Project Remaining		$ 30
Revolving Credit Facility [Member] | Letters of credit [Member]
Loss Contingencies [Line Items]
Other Commitments	192			192
Revolving Credit Facility [Member] | Commitments Expiring Less Than One Year [Member] | Letters of credit [Member]
Loss Contingencies [Line Items]
Other Commitment, Due in Next Twelve Months	20			20
Revolving Credit Facility [Member] | Commitments Expiring More Than One Year [Member] | Letters of credit [Member]
Loss Contingencies [Line Items]
Other Commitment, Due after One Year	$ 172			$ 172
Sanfeng Environmental [Member]
Loss Contingencies [Line Items]
Sale of Stock, Percentage of Ownership before Transaction	15.00%	15.00%