Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P. (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P. (Textual) [Abstract]
Minority interest in Bayview Lending Group LLC			20.00%
Carrying value of minority interest investment in Bayview Lending Group LLC	$ 104,000,000		$ 104,000,000
Outstanding principal balances of commercial mortgage loans from BLG and Bayview Financial	4,200,000,000		4,200,000,000		4,400,000,000
Amounts recorded as capitalized servicing assets for commercial mortgage loans	12,000,000		12,000,000		16,000,000
Servicing rights purchased from Bayview Financial related to residential mortgage loans	3,000,000		3,000,000		5,000,000
Outstanding principal balances of residential mortgage loans from Bayview Financial	2,900,000,000		2,900,000,000		3,100,000,000
Revenues from servicing residential and small balance commercial mortgage loans purchased from BLG and Bayview Financial	11,000,000	10,000,000	23,000,000	21,000,000
Collateralized mortgage obligations in available-for-sale investment securities portfolio securitized by Bayview Financial	12,000,000		12,000,000		15,000,000
Investment securities in held-to-maturity portfolio securitized by Bayview Financial	255,000,000		255,000,000		269,000,000
Residential mortgage loans	$ 12,300,000,000		$ 12,300,000,000		$ 13,100,000,000