Discontinued Operations and Dispositions (Consolidated Balance Sheets) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Total current assets	[1]	$ 0	$ 648
Liabilities
Total current liabilities	[1]	$ 0	317
Noncontrolling interests			141	$ 184
Contracted Power Segment | Discontinued Operations, Held-for-sale or Disposed of by Sale
Assets
Cash and cash equivalents			3
Restricted cash			14
Accounts receivable, net			9
Other current assets			5
Total current assets			31
Property, equipment, land and leasehold improvements, net			606
Intangible assets, net			9
Other noncurrent assets			2
Total assets			648
Liabilities
Accounts payable and accrued expenses			7
Current portion of long-term debt			20
Other current liabilities			1
Total current liabilities			28
Long term debt, net of current portion			283
Other noncurrent liabilities			6
Total liabilities			317
Noncontrolling interests			$ 141

[1] See Note 5, “Discontinued Operations and Dispositions”, for further discussions on assets and liabilities held for sale.