Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P. - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Bayview Lending Group And Bayview Financial [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding principal balances of mortgage servicing rights	$ 5,400,000,000		$ 5,500,000,000
Revenues from servicing	7,000,000	8,000,000
Bayview Lending Group [Member]
Schedule of Equity Method Investments [Line Items]
Minority interest in Bayview Lending Group LLC	20.00%
Carrying value of minority interest investment in Bayview Lending Group LLC	60,000,000
Bayview Financial [Member]
Schedule of Equity Method Investments [Line Items]
Revenues from servicing	26,000,000	2,000,000
Outstanding principal balances of residential mortgage loans from Bayview Financial	46,500,000,000		45,600,000,000
Investment securities in held-to-maturity portfolio securitized by Bayview Financial	$ 216,000,000		$ 220,000,000