Debt (Project Financing, Notes Payable and Others) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Russell City Project [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 591		$ 593
Debt Instrument, Interest Rate, Effective Percentage	6.20%	[1]	4.90%	[1]
Steamboat [Member]
Debt Instrument [Line Items]
Long-term Debt	407		418
Debt Instrument, Interest Rate, Effective Percentage	6.90%	[1]	6.80%	[1]
OMEC [Member]
Debt Instrument [Line Items]
Long-term Debt	325		335
Debt Instrument, Interest Rate, Effective Percentage	6.90%	[1]	6.90%	[1]
Los Esteros Project [Member]
Debt Instrument [Line Items]
Long-term Debt	275		305
Debt Instrument, Interest Rate, Effective Percentage	3.10%	[1]	3.40%	[1]
Pasadena [Member]
Debt Instrument [Line Items]
Long-term Debt	122	[2]	135	[2]
Debt Instrument, Interest Rate, Effective Percentage	8.90%	[1],[2]	8.90%	[1],[2]
Bethpage [Member]
Debt Instrument [Line Items]
Long-term Debt	82	[3]	88	[3]
Debt Instrument, Interest Rate, Effective Percentage	7.00%	[1],[3]	7.00%	[1],[3]
Gilroy note payable [Member]
Debt Instrument [Line Items]
Long-term Debt	0		15
Debt Instrument, Interest Rate, Effective Percentage	0.00%	[1]	11.20%	[1]
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt	8		12
Debt Instrument, Interest Rate, Effective Percentage	0.00%	[1]	0.00%	[1]
Project Financing Total [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 1,810		$ 1,901

[1] Our weighted average interest rate calculation includes the amortization of deferred financing costs and debt discount or premium.

[2] Represents a failed sale-leaseback transaction that is accounted for as financing transaction under U.S. GAAP.

[3] Represents a weighted average of first and second lien loans for the weighted average effective interest rates.