CONSOLIDATED STATEMENTS OF EQUITY (DEFICIT) AND REDEEMABLE NONCONTROLLING INTERESTS - USD ($) $ in Millions	Total	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests	Class A Common Stock	Class A Common Stock Common Stock	Class B Common Stock	Class B Common Stock Common Stock
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2019	$ 1,078
Increase (Decrease) in Temporary Equity
Distributions to redeemable noncontrolling interests	378
Redemption of redeemable subsidiary preferred equity, net of fees	(198)
Net income	20
Redeemable noncontrolling interest, ending balance at Mar. 31, 2020	522
Beginning balance (shares) at Dec. 31, 2019							66,830,110		24,727,682
Beginning balance at Dec. 31, 2019	1,694	$ 1,011	$ 492	$ (2)	$ 192		$ 1		$ 0
Increase (Decrease) in Stockholders' Equity
Dividends, Common Stock	(19)		(19)
Repurchases of Class A Common Stock	(176)	(176)
Repurchases of Class A Common Stock (shares)							(9,957,297)
Class A Common Stock issued pursuant to employee benefit plans (shares)							1,479,684
Class A Common Stock issued pursuant to employee benefit plans	29	29
Distributions to noncontrolling interests, net	(3)				(3)
Redemption of redeemable subsidiary preferred equity, net of fees	(198)
Net income	131		123		8
Ending balance (shares) at Mar. 31, 2020							58,352,497		24,727,682
Ending balance at Mar. 31, 2020	1,656	864	596	(2)	197		$ 1		$ 0
Increase (Decrease) in Stockholders' Equity
Dividends declared per share (USD per share)						$ 0.20		$ 0.20
Dividends paid per share (USD per share)						$ 0.20		$ 0.20
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2020	190
Increase (Decrease) in Temporary Equity
Distributions to noncontrolling interests, net	(6)
Net income	4
Redeemable noncontrolling interest, ending balance at Mar. 31, 2021	188
Beginning balance (shares) at Dec. 31, 2020						49,252,671	49,252,671	24,727,682	24,727,682
Beginning balance at Dec. 31, 2020	(1,185)	721	(1,986)	(10)	89		$ 1		$ 0
Increase (Decrease) in Stockholders' Equity
Dividends, Common Stock	(15)		(15)
Class B Common Stock converted into Class A Common Stock (shares)							510,000		(510,000)
Class B Common Stock converted into Class A Common Stock	0
Class A Common Stock issued pursuant to employee benefit plans (shares)							1,355,679
Class A Common Stock issued pursuant to employee benefit plans	14	14
Distributions to noncontrolling interests, net	(30)				(30)
Other comprehensive income	8			8
Net income	22		(12)		34
Ending balance (shares) at Mar. 31, 2021						51,118,350	51,118,350	24,217,682	24,217,682
Ending balance at Mar. 31, 2021	$ (1,186)	$ 735	$ (2,013)	$ (2)	$ 93		$ 1		$ 0
Increase (Decrease) in Stockholders' Equity
Dividends declared per share (USD per share)						$ 0.20		$ 0.20
Dividends paid per share (USD per share)						$ 0.20		$ 0.20