Residential Loans - Residential loans at fair value (Parenthetical) (Detail) (Reverse Loans [Member], USD $)	Jun. 30, 2013	Dec. 31, 2012
Reverse Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reverse loans held for sale	$ 0.0	$ 28.5

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

No definition available.

Name:	us-gaap_LoansHeldForSaleFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant