Loans - Credit Card: Risk Profile by Geographic Region and Delinquency Status (Detail) (USD $) In Millions, unless otherwise specified				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended				0 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2014 Credit Card	Dec. 31, 2013 Credit Card	Sep. 30, 2014 Credit Card	Dec. 31, 2013 Credit Card	Sep. 30, 2014 Credit Card California	Dec. 31, 2013 Credit Card California	Sep. 30, 2014 Credit Card California	Dec. 31, 2013 Credit Card California	Sep. 30, 2014 Credit Card New York	Dec. 31, 2013 Credit Card New York	Sep. 30, 2014 Credit Card New York	Dec. 31, 2013 Credit Card New York	Sep. 30, 2014 Credit Card Texas	Dec. 31, 2013 Credit Card Texas	Sep. 30, 2014 Credit Card Texas	Dec. 31, 2013 Credit Card Texas	Sep. 30, 2014 Credit Card Florida	Dec. 31, 2013 Credit Card Florida	Sep. 30, 2014 Credit Card Florida	Dec. 31, 2013 Credit Card Florida	Sep. 30, 2014 Credit Card Illinois	Dec. 31, 2013 Credit Card Illinois	Sep. 30, 2014 Credit Card Illinois	Dec. 31, 2013 Credit Card Illinois	Sep. 30, 2014 Credit Card Pennsylvania	Dec. 31, 2013 Credit Card Pennsylvania	Sep. 30, 2014 Credit Card Pennsylvania	Dec. 31, 2013 Credit Card Pennsylvania	Sep. 30, 2014 Credit Card Ohio	Dec. 31, 2013 Credit Card Ohio	Sep. 30, 2014 Credit Card Ohio	Dec. 31, 2013 Credit Card Ohio	Sep. 30, 2014 Credit Card New Jersey	Dec. 31, 2013 Credit Card New Jersey	Sep. 30, 2014 Credit Card New Jersey	Dec. 31, 2013 Credit Card New Jersey	Sep. 30, 2014 Credit Card Michigan	Dec. 31, 2013 Credit Card Michigan	Sep. 30, 2014 Credit Card Michigan	Dec. 31, 2013 Credit Card Michigan	Sep. 30, 2014 Credit Card Other	Dec. 31, 2013 Credit Card Other	Sep. 30, 2014 Credit Card Other	Dec. 31, 2013 Credit Card Other	Sep. 30, 2014 Credit Card Domestic	Dec. 31, 2013 Credit Card Domestic	Sep. 30, 2014 Credit Card Domestic	Dec. 31, 2013 Credit Card Domestic	Sep. 30, 2014 Credit Card Canada	Dec. 31, 2013 Credit Card Canada	Sep. 30, 2014 Credit Card Canada	Dec. 31, 2013 Credit Card Canada	Sep. 30, 2014 Credit Card United Kingdom	Dec. 31, 2013 Credit Card United Kingdom	Sep. 30, 2014 Credit Card United Kingdom	Dec. 31, 2013 Credit Card United Kingdom	Sep. 30, 2014 Credit Card International	Dec. 31, 2013 Credit Card International	Sep. 30, 2014 Credit Card International	Dec. 31, 2013 Credit Card International	Sep. 30, 2014 Credit Card Loans	Dec. 31, 2013 Credit Card Loans	Sep. 30, 2014 Credit Card Loans	Dec. 31, 2013 Credit Card Loans	Sep. 30, 2014 Credit Card Loans California	Dec. 31, 2013 Credit Card Loans California	Sep. 30, 2014 Credit Card Loans California	Dec. 31, 2013 Credit Card Loans California	Sep. 30, 2014 Credit Card Loans New York	Dec. 31, 2013 Credit Card Loans New York	Sep. 30, 2014 Credit Card Loans New York	Dec. 31, 2013 Credit Card Loans New York	Sep. 30, 2014 Credit Card Loans Texas	Dec. 31, 2013 Credit Card Loans Texas	Sep. 30, 2014 Credit Card Loans Texas	Dec. 31, 2013 Credit Card Loans Texas	Sep. 30, 2014 Credit Card Loans Florida	Dec. 31, 2013 Credit Card Loans Florida	Sep. 30, 2014 Credit Card Loans Florida	Dec. 31, 2013 Credit Card Loans Florida	Sep. 30, 2014 Credit Card Loans Illinois	Dec. 31, 2013 Credit Card Loans Illinois	Sep. 30, 2014 Credit Card Loans Illinois	Dec. 31, 2013 Credit Card Loans Illinois	Sep. 30, 2014 Credit Card Loans Pennsylvania	Dec. 31, 2013 Credit Card Loans Pennsylvania	Sep. 30, 2014 Credit Card Loans Pennsylvania	Dec. 31, 2013 Credit Card Loans Pennsylvania	Sep. 30, 2014 Credit Card Loans Ohio	Dec. 31, 2013 Credit Card Loans Ohio	Sep. 30, 2014 Credit Card Loans Ohio	Dec. 31, 2013 Credit Card Loans Ohio	Sep. 30, 2014 Credit Card Loans New Jersey	Dec. 31, 2013 Credit Card Loans New Jersey	Sep. 30, 2014 Credit Card Loans New Jersey	Dec. 31, 2013 Credit Card Loans New Jersey	Sep. 30, 2014 Credit Card Loans Michigan	Dec. 31, 2013 Credit Card Loans Michigan	Sep. 30, 2014 Credit Card Loans Michigan	Dec. 31, 2013 Credit Card Loans Michigan	Sep. 30, 2014 Credit Card Loans Other	Dec. 31, 2013 Credit Card Loans Other	Sep. 30, 2014 Credit Card Loans Other	Dec. 31, 2013 Credit Card Loans Other	Sep. 30, 2014 Credit Card Loans Domestic	Dec. 31, 2013 Credit Card Loans Domestic	Sep. 30, 2014 Credit Card Loans Domestic	Dec. 31, 2013 Credit Card Loans Domestic	Sep. 30, 2014 Credit Card Loans Canada	Dec. 31, 2013 Credit Card Loans Canada	Sep. 30, 2014 Credit Card Loans Canada	Dec. 31, 2013 Credit Card Loans Canada	Sep. 30, 2014 Credit Card Loans United Kingdom	Dec. 31, 2013 Credit Card Loans United Kingdom	Sep. 30, 2014 Credit Card Loans United Kingdom	Dec. 31, 2013 Credit Card Loans United Kingdom	Sep. 30, 2014 Credit Card Loans International	Dec. 31, 2013 Credit Card Loans International	Sep. 30, 2014 Credit Card Loans International	Dec. 31, 2013 Credit Card Loans International	Sep. 30, 2014 Credit Card Acquired Loans	Dec. 31, 2013 Credit Card Acquired Loans	Sep. 30, 2014 Credit Card Acquired Loans	Dec. 31, 2013 Credit Card Acquired Loans	Sep. 30, 2014 Credit Card Acquired Loans California	Dec. 31, 2013 Credit Card Acquired Loans California	Sep. 30, 2014 Credit Card Acquired Loans California	Dec. 31, 2013 Credit Card Acquired Loans California	Sep. 30, 2014 Credit Card Acquired Loans New York	Dec. 31, 2013 Credit Card Acquired Loans New York	Sep. 30, 2014 Credit Card Acquired Loans New York	Dec. 31, 2013 Credit Card Acquired Loans New York	Sep. 30, 2014 Credit Card Acquired Loans Texas	Dec. 31, 2013 Credit Card Acquired Loans Texas	Sep. 30, 2014 Credit Card Acquired Loans Texas	Dec. 31, 2013 Credit Card Acquired Loans Texas	Sep. 30, 2014 Credit Card Acquired Loans Florida	Dec. 31, 2013 Credit Card Acquired Loans Florida	Sep. 30, 2014 Credit Card Acquired Loans Florida	Dec. 31, 2013 Credit Card Acquired Loans Florida	Sep. 30, 2014 Credit Card Acquired Loans Illinois	Dec. 31, 2013 Credit Card Acquired Loans Illinois	Sep. 30, 2014 Credit Card Acquired Loans Illinois	Dec. 31, 2013 Credit Card Acquired Loans Illinois	Sep. 30, 2014 Credit Card Acquired Loans Pennsylvania	Dec. 31, 2013 Credit Card Acquired Loans Pennsylvania	Sep. 30, 2014 Credit Card Acquired Loans Pennsylvania	Dec. 31, 2013 Credit Card Acquired Loans Pennsylvania	Sep. 30, 2014 Credit Card Acquired Loans Ohio	Dec. 31, 2013 Credit Card Acquired Loans Ohio	Sep. 30, 2014 Credit Card Acquired Loans Ohio	Dec. 31, 2013 Credit Card Acquired Loans Ohio	Sep. 30, 2014 Credit Card Acquired Loans New Jersey	Dec. 31, 2013 Credit Card Acquired Loans New Jersey	Sep. 30, 2014 Credit Card Acquired Loans New Jersey	Dec. 31, 2013 Credit Card Acquired Loans New Jersey	Sep. 30, 2014 Credit Card Acquired Loans Michigan	Dec. 31, 2013 Credit Card Acquired Loans Michigan	Sep. 30, 2014 Credit Card Acquired Loans Michigan	Dec. 31, 2013 Credit Card Acquired Loans Michigan	Sep. 30, 2014 Credit Card Acquired Loans Other	Dec. 31, 2013 Credit Card Acquired Loans Other	Sep. 30, 2014 Credit Card Acquired Loans Other	Dec. 31, 2013 Credit Card Acquired Loans Other	Sep. 30, 2014 Credit Card Acquired Loans Domestic	Dec. 31, 2013 Credit Card Acquired Loans Domestic	Sep. 30, 2014 Credit Card Acquired Loans Domestic	Dec. 31, 2013 Credit Card Acquired Loans Domestic	Sep. 30, 2014 Credit Card Acquired Loans Canada	Dec. 31, 2013 Credit Card Acquired Loans Canada	Sep. 30, 2014 Credit Card Acquired Loans Canada	Dec. 31, 2013 Credit Card Acquired Loans Canada	Sep. 30, 2014 Credit Card Acquired Loans United Kingdom	Dec. 31, 2013 Credit Card Acquired Loans United Kingdom	Sep. 30, 2014 Credit Card Acquired Loans United Kingdom	Dec. 31, 2013 Credit Card Acquired Loans United Kingdom	Sep. 30, 2014 Credit Card Acquired Loans International	Dec. 31, 2013 Credit Card Acquired Loans International	Sep. 30, 2014 Credit Card Acquired Loans International	Dec. 31, 2013 Credit Card Acquired Loans International
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-investment	$ 201,592	$ 197,199	$ 191,814			$ 80,631	$ 81,305			$ 8,042	$ 7,940			$ 5,295	$ 5,277			$ 5,061	$ 4,993			$ 4,445	$ 4,325			$ 3,537	$ 3,603			$ 3,340	$ 3,442			$ 2,880	$ 2,965			$ 2,697	$ 2,736			$ 2,539	$ 2,595			$ 35,307	$ 35,379			$ 73,143	$ 73,255			$ 4,039	$ 4,503			$ 3,449	$ 3,547			$ 7,488	$ 8,050			$ 80,603	$ 81,242			$ 8,039	$ 7,934			$ 5,292	$ 5,271			$ 5,059	$ 4,989			$ 4,443	$ 4,321			$ 3,536	$ 3,600			$ 3,338	$ 3,439			$ 2,879	$ 2,963			$ 2,696	$ 2,734			$ 2,538	$ 2,593			$ 35,295	$ 35,348			$ 73,115	$ 73,192			$ 4,039	$ 4,503			$ 3,449	$ 3,547			$ 7,488	$ 8,050			$ 28	$ 63			$ 3	$ 6			$ 3	$ 6			$ 2	$ 4			$ 2	$ 4			$ 1	$ 3			$ 2	$ 3			$ 1	$ 2			$ 1	$ 2			$ 1	$ 2			$ 12	$ 31			$ 28	$ 63			$ 0	$ 0			$ 0	$ 0			$ 0	$ 0
Percentage of portfolio				100.00%	100.00%			10.00%	9.80%			6.60%	6.50%			6.30%	6.10%			5.50%	5.30%			4.40%	4.40%			4.10%	4.20%			3.60%	3.60%			3.30%	3.40%			3.10%	3.20%			43.80%	43.60%			90.70%	90.10%			5.00%	5.50%			4.30%	4.40%			9.30%	9.90%			100.00%	99.90%			10.00%	9.80%			6.60%	6.50%			6.30%	6.10%			5.50%	5.30%			4.40%	4.40%			4.10%	4.20%			3.60%	3.60%			3.30%	3.40%			3.10%	3.20%			43.80%	43.50%			90.70%	90.00%			5.00%	5.50%			4.30%	4.40%			9.30%	9.90%			0.00%	0.10%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%			0.00%	0.10%			0.00%	0.10%			0.00%	0.00%			0.00%	0.00%			0.00%	0.00%
30 plus day delinquencies	5,556	5,833				2,653	2,881																																											2,347	2,514											306	367
90 plus day delinquencies	$ 1,637	$ 1,872				$ 1,147	$ 1,328																																											$ 1,033	$ 1,187											$ 114	$ 141
Financing Receivable, Percent Past Due	2.76%	2.96%				3.29%	3.54%
Greater than 90 Days (as percent)	0.81%	0.95%				1.42%	1.63%