Consolidated Statements of Income - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Non-interest revenues
Other		$ 363	$ 377
Total non-interest revenues		8,305	7,877
Interest income
Interest on loans		2,725	2,326
Interest and dividends on investment securities		33	21
Deposits with banks and other		196	115
Total interest income		2,954	2,462
Interest expense
Deposits		399	270
Long-term debt and other		496	351
Total interest expense		895	621
Net interest income		2,059	1,841
Total revenues net of interest expense		10,364	9,718
Provisions for losses
Charge card		253	242
Card Member loans provisions		525	499
Other		31	34
Total provisions for losses		809	775
Total revenues net of interest expense after provisions for losses		9,555	8,943
Expenses
Marketing and business development		1,573	1,345
Card Member rewards		2,451	2,347
Card Member services		550	409
Salaries and employee benefits		1,422	1,326
Other, net		1,601	1,434
Total expenses		7,597	6,861
Pretax income		1,958	2,082
Income tax provision		408	448
Net income		$ 1,550	$ 1,634
Earnings Per Common Share, Basic (Note 15) [Abstract]
Net income attributable to common shareholders	[1]	$ 1.81	$ 1.86
Earnings Per Common Share, Diluted (Note 15) [Abstract]
Net income attributable to common shareholders	[1]	$ 1.8	$ 1.86
Average common shares outstanding for earnings per common share:
Basic		841	859
Diluted		843	861
Cash dividends declared per common share		$ 0.39	$ 0.35
Discount Revenue
Non-interest revenues
Revenues and Fees		$ 6,195	$ 5,889
Net Card Fees
Non-interest revenues
Revenues and Fees		944	830
Other Fees and Commissions
Non-interest revenues
Revenues and Fees		$ 803	$ 781

[1] Represents net income less (i) earnings allocated to participating share awards of $ 11 million and $ 13 million for the three months ended March 31 , 2019 and 2018 , respectively, and (ii) dividends on preferred shares of $ 21 million for both the three months ended March 31 , 2019 and 2018 .