Derivatives (Details) (Not designated as hedging instruments, USD $)	Mar. 31, 2012	Dec. 31, 2011
Derivatives
Asset	$ 173,000,000	$ 235,000,000
Liability	24,000,000	132,000,000
Netting adjustments:
Offsetting receivables/payables, asset	(12,000,000)	(32,000,000)
Offsetting receivables/payables, liability	(12,000,000)	(32,000,000)
Cash collateral (paid)/received	(10,000,000)	(6,000,000)
Cash collateral paid/ (received)	3,000,000	(54,000,000)
Net fair value of derivative instruments, asset	151,000,000	197,000,000
Net fair value of derivative instruments, liability	15,000,000	46,000,000
Cash collateral posted for derivative agreements that did not qualify for net presentation	1,000,000	13,000,000
Interest rate lock commitments
Derivatives
Asset	128,000,000	184,000,000
Notional	5,464,000,000	7,095,000,000
Forward delivery commitments
Derivatives
Notional	5,800,000,000	8,300,000,000
Forward delivery commitments not subject to master netting arrangements
Derivatives
Asset	5,000,000	6,000,000
Liability	2,000,000	27,000,000
Notional	2,030,000,000	3,897,000,000
Forward delivery commitments subject to master netting arrangements
Derivatives
Asset	25,000,000	32,000,000
Liability	12,000,000	100,000,000
Notional	11,211,000,000	11,893,000,000
Option contracts
Derivatives
Asset	2,000,000	2,000,000
Notional	870,000,000	845,000,000
MSR-related agreements
Derivatives
Asset	2,000,000	6,000,000
Notional	1,100,000,000	1,100,000,000
Interest rate contracts
Derivatives
Asset	1,000,000	1,000,000
Liability		1,000,000
Notional	592,000,000	477,000,000
Convertible note-related agreements
Derivatives
Asset	10,000,000	4,000,000
Liability	$ 10,000,000	$ 4,000,000
Convertible note-related agreements | Common Stock
Derivatives
Notional amount (in shares)	9,688,100	9,688,100