Schedule IV - Reconciliation of Mortgage Loans on Real Estate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Mortgage Loans on Real Estate [Abstract]
Balance at January 1,	$ 4,428,500	$ 2,047,223	$ 141,500
Additions during period:
Loan fundings	7,203,145	3,067,263	2,327,914
Amortization of deferred fees and expenses	36,052	19,785	5,965
Unrealized gain on foreign currency translation			796
Valuation allowance on loans held-for-sale			1,259
Deductions during period:
Collections of principal	(2,407,920)	(564,183)	(383,647)
Unrealized loss on foreign currency translation	(149,269)	(52,076)
Deferred origination fees and expenses	(33,501)	(35,449)	(25,402)
Loans sold		(27,063)	(21,162)
Transfers to other assets		(27,000)
Balance at December 31,	$ 9,077,007	$ 4,428,500	$ 2,047,223