Goodwill and other intangible assets - by Business Segment (Details) - USD ($) $ in Millions	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill	$ 47,405	$ 47,476	$ 47,647	$ 47,970	$ 48,110	$ 48,081
Consumer & Community Banking
Goodwill [Line Items]
Goodwill	30,851		30,941
Corporate & Investment Bank
Goodwill [Line Items]
Goodwill	6,771		6,780
Commercial Banking
Goodwill [Line Items]
Goodwill	2,861		2,861
Asset Management
Goodwill [Line Items]
Goodwill	6,922		6,964
Corporate
Goodwill [Line Items]
Goodwill	$ 0		$ 101