Computation of Basic/Diluted Earnings Per Common Share - (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Consolidated net income	$ 435	$ 280	$ 395	$ 639	$ 876	$ 619	$ 1,110	$ 2,135
Denominator:
Denominator for basic earnings per common share - weighted-average common shares outstanding (in shares)	782			778			781	777
Effect of dilutive stock options and awards under the treasury stock method (in shares)	7			5			7	7
Denominator for diluted earnings per common share—weighted-average common shares outstanding plus dilutive common shares under the treasury stock method (in shares)	789			783			788	784
Basic earnings per common share (in dollars per share)	$ 0.56			$ 0.82			$ 1.42	$ 2.75
Diluted earnings per common share (in dollars per share)	$ 0.55			$ 0.82			$ 1.41	$ 2.72