Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common stock	Paid-in capital	Retained earnings	Accumulated other comprehensive loss
Beginning of period at Dec. 31, 2019		$ 168	$ 0	$ 8,748	$ (97)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased		(1)	0	(479)
Net earnings	$ 1,873			1,873
Dividends declared				(465)
Stock compensation			10	(36)
Other				11
Other comprehensive loss, net of tax	(20)				(20)
End of period at Jun. 30, 2020	$ 9,712	167	10	9,652	(117)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends declared per share	$ 2.77
Beginning of period at Mar. 31, 2020		167	0	9,011	(116)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased		0	0	(131)
Net earnings	$ 1,005			1,005
Dividends declared				(242)
Stock compensation			10	9
Other				0
Other comprehensive loss, net of tax	(1)				(1)
End of period at Jun. 30, 2020	9,712	167	10	9,652	(117)
Beginning of period at Dec. 31, 2020	10,579	167	58	10,482	(128)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased		(7)	60	(2,089)
Net earnings	3,232			3,232
Dividends declared				(489)
Stock compensation			2	8
Other				0
Other comprehensive loss, net of tax	(4)				(4)
End of period at Jun. 30, 2021	$ 11,172	160	0	11,144	(132)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends declared per share	$ 3.02
Beginning of period at Mar. 31, 2021		161	8	10,487	(131)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased		(1)	21	(134)
Net earnings	$ 1,037			1,037
Dividends declared				(254)
Stock compensation			13	8
Other				0
Other comprehensive loss, net of tax	(1)				(1)
End of period at Jun. 30, 2021	$ 11,172	$ 160	$ 0	$ 11,144	$ (132)