Business Combinations (Details) (USD $)	12 Months Ended		3 Months Ended
	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2014 PB Capital	Jun. 30, 2013 PB Capital
Business Acquisitions
Purchase price, paid in cash				$ 3,700,000,000
Loans acquired excluding the effects of purchase accounting adjustments				3,500,000,000
Fair value of net assets acquired				3,400,000,000
Goodwill	3,228,000,000	3,227,000,000		227,000,000
Term for change in provisional fair value estimates of the loans acquired after closing date of acquisition	1 year
Goodwill, adjustments			$ 0