Equity Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Equity Table [Line Items]
Beginning Balance	114,355,519
Repurchase of common stock		(1,200,000)
Ending Balance	115,285,528
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 2,096	$ 2,315
Net loss	(462)	(99)
Other comprehensive income (loss)	(1)	2
Repurchase of common stock		(20)
Stock-based compensation	6	8
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	0	0
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(4)	$ (6)
Cash dividends declared per share		$ 0.09
Dividends declared, APIC	0	$ (10)
Dividends declared	(1)	(11)
Ending Balance	$ 1,634	$ 2,189
Common Stock
Statement of Equity Table [Line Items]
Beginning Balance	114,400,000	114.6
Repurchase of common stock		(1.2)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	1,400,000	1.2
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligations	(500,000)	(0.4)
Ending Balance	115,300,000	114.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 1	$ 1
Repurchase of common stock		0
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	0	0
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	0	0
Ending Balance	1	1
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	4,842	4,869
Repurchase of common stock		(20)
Stock-based compensation	6	8
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(4)	(6)
Ending Balance	4,844	4,841
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(2,695)	(2,507)
Net loss	(462)	(99)
Ending Balance	(3,157)	(2,606)
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(56)	(52)
Other comprehensive income (loss)	(1)	2
Ending Balance	(57)	(50)
Non- controlling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	4	4
Net loss	0	0
Dividends declared, Noncontrolling Interest	(1)	(1)
Ending Balance	$ 3	$ 3