SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION - Rollforward of Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real estate:
Balance at the beginning of the period	$ 2,277,457	$ 1,831,799	$ 1,066,496
Acquisitions	150,782	482,125	792,510
Real estate acquired through loan receivable foreclosure	10,100	0	0
Addition due to consolidation of variable interest entity	0	10,700	0
Improvements	1,003	3,689	1,471
Impairment	(39,058)	0	0
Sale of real estate	(107,930)	(29,395)	(23,265)
Foreign currency translation	4,623	(16,944)	0
Write-off of fully depreciated assets	(4,226)	(4,517)	(5,413)
Balance at the end of the year	2,292,751	2,277,457	1,831,799
Accumulated depreciation:
Balance at the beginning of the period	(237,841)	(185,994)	(151,078)
Depreciation expense	(64,463)	(59,864)	(42,021)
Impairment	9,247	0	0
Sale of real estate	6,023	3,384	1,692
Foreign currency translation	(4)	116	0
Write-off of fully depreciated assets	4,226	4,517	5,413
Balance at the end of the year	$ (282,812)	$ (237,841)	$ (185,994)