Loans Receivable - Allocation of Loans Receivable by Loan Type and Internal Risk Ratings (Parenthetical) (Detail) (Senior Mortgages Loans [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Senior Mortgages Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contiguous subordinated loans	$ 68.6