CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	ACCUMULATED OTHER COMPREHENSIVE LOSS	ACCUMULATED DEFICIT	ACCUMULATED DEFICIT Cumulative Effect, Period of Adoption, Adjustment
Balance at beginning of period at Dec. 31, 2019		$ 1,090	$ 21,874	$ (2,680)	$ (6,814)	$ 9
Increase (Decrease) in Stockholders' Equity
Issuance of common stock through incentive and benefit plans		7
Shares withheld to satisfy tax withholdings			(35)
Share-based compensation and other, net			99
Dividends declared			(562)
Other comprehensive income (loss)	$ (222)			(222)
Net income	691				691
Other					5
Balance at end of period at Jun. 30, 2020	$ 13,462	1,097	21,376	(2,902)	(6,109)
Increase (Decrease) in Stockholders' Equity
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.50
Balance at beginning of period at Mar. 31, 2020		1,098	21,634	(2,955)	(6,486)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock through incentive and benefit plans		(1)
Shares withheld to satisfy tax withholdings			(2)
Share-based compensation and other, net			20
Dividends declared			(276)
Other comprehensive income (loss)	$ 53			53
Net income	377				377
Other					0
Balance at end of period at Jun. 30, 2020	$ 13,462	1,097	21,376	(2,902)	(6,109)
Increase (Decrease) in Stockholders' Equity
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.25
Balance at beginning of period at Dec. 31, 2020	$ 11,162	1,097	20,909	(2,813)	(8,031)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock through incentive and benefit plans		8
Shares withheld to satisfy tax withholdings			(42)
Share-based compensation and other, net			64
Dividends declared			(570)
Other comprehensive income (loss)	103			103
Net income	981				981
Other					0
Balance at end of period at Jun. 30, 2021	$ 11,706	1,105	20,361	(2,710)	(7,050)
Increase (Decrease) in Stockholders' Equity
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.50
Balance at beginning of period at Mar. 31, 2021		1,106	20,598	(2,845)	(7,556)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock through incentive and benefit plans		(1)
Shares withheld to satisfy tax withholdings			(3)
Share-based compensation and other, net			44
Dividends declared			(278)
Other comprehensive income (loss)	$ 135			135
Net income	506				506
Other					0
Balance at end of period at Jun. 30, 2021	$ 11,706	$ 1,105	$ 20,361	$ (2,710)	$ (7,050)
Increase (Decrease) in Stockholders' Equity
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.25