Transfers of Residential Loans - Summary of Cash Flows Related to Transfers of Residential Loans Accounted for as Sales (Detail) (USD $) In Thousands, unless otherwise specified					3 Months Ended	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2013 Servicing Arrangements Associated with Transfers of Forward Loans [Member]	Sep. 30, 2013 Residential Loan Transfers Accounted for as Sales [Member]	Sep. 30, 2013 Residential Loan Transfers Accounted for as Sales [Member]
Residential Loan Transfers Line Items
Proceeds received from transfers					$ 6,490,299	$ 10,122,117
Servicing fees collected					3,349	3,796
Servicing Rights, Net	1,189,078	242,712		124,977
Servicer and protective advances, net	1,186,066	173,047		1,555
Recievables,Net	253,959	259,009		251
Total assets	16,807,299	10,978,177	4,005,923	126,783
Unpaid Principal Balance of Transferred Loans				$ 9,746,851