Schedule IV - Reconciliation of Mortgage Loans on Real Estate (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Mortgage Loans on Real Estate [Abstract]
Balance at January 1,	$ 2,047,223	$ 141,500	$ 869,269
Additions during period:
Consolidation (deconsolidation) of subsidiary			(645,163)
Loan fundings	3,067,263	2,327,914	26
Amortization of deferred fees and expenses	19,785	5,965	180
Unrealized gain (loss) on foreign currency translation		796
Valuation allowance on loans held-for-sale	1,300	1,259
Recovery of provision for loan losses			36,147
Deductions during period:
Collections of principal	(564,183)	(383,647)	(118,959)
Unrealized gain (loss) on foreign currency translation	(52,076)
Deferred origination fees and expenses	(35,449)	(25,402)
Loans sold	(27,063)	(21,162)
Transfers to other assets	(27,000)
Balance at December 31,	$ 4,428,500	$ 2,047,223	$ 141,500