Stockholders' Equity - Changes in Stockholders Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Changes in Stockholders' Equity
Beginning balance	$ 333,775	$ 236,447	$ 285,970	$ 201,875	$ 259,151
Other comprehensive income (loss)	9,913	2,075	12,367	1,122
Net income	21,187	15,328	56,478	39,244	76,482	$ 49,868
Ending balance	369,631	259,151	369,631	259,151	369,631	259,151
Common stock
Changes in Stockholders' Equity
Beginning balance	112	110	111	109	110
Stock-based compensation and issuance of employee benefit plan stock	0	0	1	1
Ending balance	112	110	112	110	112	110
Treasury stock
Changes in Stockholders' Equity
Beginning balance	(7,837)	(7,837)	(7,837)	(7,837)	(7,837)
Ending balance	(7,837)	(7,837)	(7,837)	(7,837)	(7,837)	(7,837)
Additional paid-in capital
Changes in Stockholders' Equity
Beginning balance	130,923	110,633	120,864	99,025	115,934
Stock-based compensation and issuance of employee benefit plan stock	4,756	5,301	14,815	16,909
Ending balance	135,679	115,934	135,679	115,934	135,679	115,934
Accumulated other comprehensive income (loss)
Changes in Stockholders' Equity
Beginning balance	2,420	(3,993)	(34)	(3,040)	(1,918)
Other comprehensive income (loss)	9,913	2,075	12,367	1,122
Ending balance	12,333	(1,918)	12,333	(1,918)	12,333	(1,918)
Retained earnings
Changes in Stockholders' Equity
Beginning balance	208,157	137,534	172,866	113,618	152,862
Net income	21,187	15,328	56,478	39,244
Ending balance	$ 229,344	$ 152,862	$ 229,344	$ 152,862	$ 229,344	$ 152,862