Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016		Jun. 30, 2017		Jun. 30, 2016
Non-interest revenues
Discount revenue	$ 4,815		$ 4,824		$ 9,334		$ 9,467
Net card fees	771		715		1,519		1,414
Other fees and commissions	752		702		1,465		1,382
Other	439		545		848		1,031
Total non-interest revenues	6,777		6,786		13,166		13,294
Interest income
Interest on loans	1,947		1,818		3,807		3,756
Interest and dividends on investment securities	23		34		46		70
Deposits with banks and other	82		33		142		64
Total interest income	2,052		1,885		3,995		3,890
Interest expense
Deposits	176		150		325		300
Long-term debt and other	346		286		640		561
Total interest expense	522		436		965		861
Net interest income	1,530		1,449		3,030		3,029
Total revenues net of interest expense	8,307		8,235		16,196		16,323
Provisions for losses
Charge card	163		153		376		322
Card Member loans	404		285		741		512
Other	17		25		40		63
Total provisions for losses	584		463		1,157		897
Total revenues net of interest expense after provisions for losses	7,723		7,772		15,039		15,426
Expenses
Marketing and promotion	830		788		1,530		1,515
Card Member Rewards	1,926		1,766		3,733		3,469
Card Member services and other	349		281		670		563
Salaries and employee benefits	1,293		1,451		2,557		2,789
Other, net	1,376		470		2,783		1,890
Total expenses	5,774		4,756		11,273		10,226
Pretax income	1,949		3,016		3,766		5,200
Income tax provision	609		1,001		1,189		1,759
Income from continuing operations	1,340		2,015		2,577		3,441
Net income	$ 1,340		$ 2,015		$ 2,577		$ 3,441
Earnings Per Common Share, Basic (Note 15) [Abstract]
Net income attributable to common shareholders	$ 1.47	[1]	$ 2.11	[1]	$ 2.81	[2]	$ 3.55	[2]
Earnings Per Common Share, Diluted (Note 15) [Abstract]
Net income attributable to common shareholders	$ 1.47	[1]	$ 2.1	[1]	$ 2.8	[2]	$ 3.54	[2]
Average common shares outstanding for earnings per common share:
Basic	890		938		895		949
Diluted	893		941		898		952
Cash dividends declared per common share	$ 0.32		$ 0.29		$ 0.64		$ 0.58

[1] Represents net income less (i) earnings allocated to participating share awards of $ 11 million and $ 17 million for the three months ended June 30 , 2017 and 2016 , respectively, and (ii) dividends on preferred shares of $ 19 million for both the three months ended June 30 , 2017 and 2016 .

[2] Represents net income less (i) earnings allocated to participating share awards of $ 21 million and $ 28 million for the six months ended June 30 , 2017 and 2016 , respectively, and (ii) dividends on preferred shares of $ 40 million for both the six months ended June 30 , 2017 and 2016 .