Reportable Operating Segments and Geographic Operations - Selected Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total non-interest revenues	$ 54,865	$ 50,406	$ 47,381
Revenue from contracts with customers	41,304	38,825	37,218
Interest income	25,598	23,795	19,983
Interest expense	8,234	8,252	6,849
Net interest income	17,364	15,543	13,134
Total revenues net of interest expense	72,229	65,949	60,515
Provisions	5,256	5,185	4,923
Total revenues net of interest expense after provisions for credit losses	66,973	60,764	55,592
Card Member rewards, business development and Card Member services	30,923	27,267	24,992
Marketing	6,252	6,040	5,213
Salaries and employee benefits and other operating expenses	16,003	14,562	14,874
Total expenses	53,178	47,869	45,079
Pretax income (loss)	13,795	12,895	10,513
Total assets	300,052	271,461	261,108
Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	54,838	50,454	47,487
Revenue from contracts with customers	41,332	38,857	37,255
Interest income	23,306	21,187	17,797
Interest expense	5,645	5,410	4,566
Net interest income	17,661	15,777	13,231
Total revenues net of interest expense	72,499	66,231	60,718
Provisions	5,256	5,186	4,922
Total revenues net of interest expense after provisions for credit losses	67,243	61,045	55,796
Card Member rewards, business development and Card Member services	30,883	27,224	24,946
Marketing	6,230	6,016	5,193
Salaries and employee benefits and other operating expenses	14,081	12,494	12,734
Total expenses	51,194	45,734	42,873
Pretax income (loss)	16,049	15,311	12,923
Total assets	254,911	233,788	228,467
Corporate and Other
Segment Reporting Information [Line Items]
Total non-interest revenues	27	(48)	(106)
Revenue from contracts with customers	(29)	(32)	(37)
Interest income	2,292	2,608	2,186
Interest expense	2,589	2,842	2,283
Net interest income	(297)	(234)	(97)
Total revenues net of interest expense	(270)	(282)	(203)
Provisions	0	(1)	1
Total revenues net of interest expense after provisions for credit losses	(270)	(281)	(204)
Card Member rewards, business development and Card Member services	40	43	46
Marketing	22	24	20
Salaries and employee benefits and other operating expenses	1,922	2,068	2,140
Total expenses	1,984	2,135	2,206
Pretax income (loss)	(2,254)	(2,416)	(2,410)
Total assets	45,141	37,673	32,641
USCS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	22,307	20,137	18,464
Revenue from contracts with customers	15,626	14,481	13,715
Interest income	15,655	14,430	12,336
Interest expense	3,148	3,140	2,684
Net interest income	12,507	11,290	9,652
Total revenues net of interest expense	34,814	31,427	28,116
Provisions	2,967	3,029	2,855
Total revenues net of interest expense after provisions for credit losses	31,847	28,398	25,261
Card Member rewards, business development and Card Member services	16,557	14,329	12,808
Marketing	3,187	3,051	2,585
Salaries and employee benefits and other operating expenses	5,293	4,641	4,435
Total expenses	25,037	22,021	19,828
Pretax income (loss)	6,810	6,377	5,433
Total assets	122,968	114,228	107,158
CS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	13,654	13,219	12,931
Revenue from contracts with customers	11,856	11,559	11,379
Interest income	5,077	4,374	3,328
Interest expense	1,805	1,734	1,483
Net interest income	3,272	2,640	1,845
Total revenues net of interest expense	16,926	15,859	14,776
Provisions	1,380	1,389	1,313
Total revenues net of interest expense after provisions for credit losses	15,546	14,470	13,463
Card Member rewards, business development and Card Member services	7,166	6,504	6,332
Marketing	1,331	1,319	1,090
Salaries and employee benefits and other operating expenses	3,381	3,142	3,180
Total expenses	11,878	10,965	10,602
Pretax income (loss)	3,668	3,505	2,861
Total assets	63,168	58,969	55,361
ICS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	11,819	10,369	9,472
Revenue from contracts with customers	7,544	6,766	6,155
Interest income	2,534	2,331	2,076
Interest expense	1,353	1,239	1,118
Net interest income	1,181	1,092	958
Total revenues net of interest expense	13,000	11,461	10,430
Provisions	831	726	727
Total revenues net of interest expense after provisions for credit losses	12,169	10,735	9,703
Card Member rewards, business development and Card Member services	5,950	5,243	4,588
Marketing	1,319	1,235	1,081
Salaries and employee benefits and other operating expenses	3,297	3,226	3,061
Total expenses	10,566	9,704	8,730
Pretax income (loss)	1,603	1,031	973
Total assets	50,089	42,879	42,234
GMNS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	7,058	6,729	6,620
Revenue from contracts with customers	6,306	6,051	6,006
Interest income	40	52	57
Interest expense	(661)	(703)	(719)
Net interest income	701	755	776
Total revenues net of interest expense	7,759	7,484	7,396
Provisions	78	42	27
Total revenues net of interest expense after provisions for credit losses	7,681	7,442	7,369
Card Member rewards, business development and Card Member services	1,210	1,148	1,218
Marketing	393	411	437
Salaries and employee benefits and other operating expenses	2,110	1,485	2,058
Total expenses	3,713	3,044	3,713
Pretax income (loss)	3,968	4,398	3,656
Total assets	$ 18,686	$ 17,712	$ 23,714