Servicing of Residential Loans - Summary of Activity in Servicing Rights Carried at Fair Value (Parenthetical) (Detail) (Purchases at Fair Value [Member], Bank of America Asset Purchase [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2013
Purchases at Fair Value [Member] | Bank of America Asset Purchase [Member]
Servicing Assets at Fair Value [Line Items]
Servicing rights	$ 495,700