Equity - Statements of Equity with dividends per share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Balance at beginning of period	$ 2,972
Repurchases of common stock, net	(14)
Balance at end of period	2,663
Dividends declared, common stock (in dollars per share)		$ 0.63
Common Stock
Balance at beginning of period	1	$ 1
Balance at end of period	1	1
Additional Paid-in Capital
Balance at beginning of period	1,150	1,137
Share-based compensation, net of issuance	5	5
Balance at end of period	1,155	1,142
Treasury Stock
Balance at beginning of period	(1,024)	(1,040)
Repurchases of common stock, net	(14)
Share-based compensation, net of issuance	16	12
Balance at end of period	(1,022)	(1,028)
Accumulated Other Comprehensive Loss
Balance at beginning of period	(1,133)	(1,158)
Other comprehensive income (loss)	(31)	(164)
Balance at end of period	(1,164)	(1,322)
Retained Earnings
Balance at beginning of period	3,957	3,780
Net income	(246)	75
Dividends declared, common stock	(44)	(42)
Balance at end of period	3,667	3,813
Non-Redeemable Non-Controlling Interests
Balance at beginning of period	21	21
Net income	4	3
Other comprehensive income (loss)	1	(3)
Balance at end of period	$ 26	$ 21