Segment Reporting - Reconciliation of Segment Adjusted EBITDA (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Earnings (loss) in unconsolidated investments, net	$ (10)			$ (4)			$ (16)	$ 13
Unrealized gain (loss) on derivatives	2			1			(8)	1
Impairment expense	0			(3)			0	(7)
Adjustments for unconsolidated investments	5			0			8	0
Other	(13)			(1)			(15)	(2)
Interest expense, net of interest income	(26)			(28)			(76)	(80)
Depreciation, amortization and accretion	(85)			(63)			(257)	(188)
Net loss before income tax	(70)			(28)			(138)	(32)
Income tax provision	(1)			(3)			(9)	(14)
Net loss	(71)	$ (30)	$ (46)	(31)	$ (2)	$ (13)	(147)	(46)
Interest expense, net of interest income
Segment Reporting Information [Line Items]
Earnings (loss) in unconsolidated investments, net	(9)			(9)			(21)	(28)
Income tax provision
Segment Reporting Information [Line Items]
Earnings (loss) in unconsolidated investments, net	0			(1)			0	(1)
Depreciation, amortization and accretion
Segment Reporting Information [Line Items]
Earnings (loss) in unconsolidated investments, net	(8)			(8)			(21)	(26)
Gain (loss) on derivatives
Segment Reporting Information [Line Items]
Earnings (loss) in unconsolidated investments, net	(1)			4			(13)	7
Operating Segments | Operating Business
Segment Reporting Information [Line Items]
Adjusted EBITDA	86			86			311	294
Earnings (loss) in unconsolidated investments, net	2			1			15	30
Impairment expense				0			0	0
Income tax provision	(1)			(3)			(5)	(6)
Net loss	(31)			(1)			(34)	40
Operating Segments | Development Investment
Segment Reporting Information [Line Items]
Adjusted EBITDA	(10)			(1)			(29)	(13)
Earnings (loss) in unconsolidated investments, net	0			0			0	0
Impairment expense				0			(2)	0
Income tax provision	0			(1)			0	(1)
Net loss	(11)			(2)			(30)	(14)
Corporate, Other and Eliminations
Segment Reporting Information [Line Items]
Adjusted EBITDA	(21)			(6)			(46)	(2)
Earnings (loss) in unconsolidated investments, net	(12)			(5)			(31)	(17)
Impairment expense				(3)			0	(7)
Income tax provision	0			0			(4)	(8)
Net loss	(40)			(30)			(113)	(86)
Reconciling Amounts
Segment Reporting Information [Line Items]
Adjusted EBITDA	10			1			29	13
Earnings (loss) in unconsolidated investments, net	0			0			0	0
Impairment expense				0			2	0
Income tax provision	0			1			0	1
Net loss	$ 11			$ 2			$ 30	$ 14