Earnings Per Share - Reconciliation of Information Used to Compute Basic and Diluted EPS (Details) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
	Oct. 15, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Income (loss) from continuing operations attributable to common shareholders		$ (84)	$ (136)	$ 69	$ (50)
Income (loss) from discontinued operations after income taxes		(12)	15	50	116
Net income (loss)		(96)	(121)	119	66
Less: preferred stock dividends declared		0	0	(1)	(1)
Net income available to the Company's common shareholders - basic		(96)	(121)	118	65
Add: Interest expense related to convertible notes		0	3	0	6
Net income available to the Company's common shareholders - diluted		$ (96)	$ (118)	$ 118	$ 71
Average shares outstanding - basic (in shares)		436	445	436	458
Effect of dilutive securities:
Stock options (in shares)		0	0	0	0
Stock and performance awards (in shares)		0	0	4	4
Convertible notes (in shares)		0	0	0	0
Average shares outstanding - diluted (in shares)		436	445	440	462
Common stock outstanding (in shares)		436	440	436	440
Incremental common shares attributable to dilutive effect of accelerated share repurchase agreements (in shares)					8
Convertible notes
Effect of dilutive securities:
Number of shares of common stock previously attributable to the convertible notes (in shares)	15	0	14	0	14