SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION - Analysis of Carrying Amount of Real Estate Properties and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate Properties
Loss on asset impairment	$ (58,476)	$ (17,162)	$ (185,067)
Balance at the end of the year	2,856,890
Accumulated Depreciation
Balance at the beginning of the year	898,939	1,030,445	895,059
Additions	101,647	144,844	164,815
Loss on asset impairment	(119)	0	(6,423)
Properties reclassified to discontinued operations			5,724
Disposals	(245,212)	(276,350)	(28,730)
Balance at the end of the year	755,255	898,939	1,030,445
Real Estate
Real Estate Properties
Balance at the beginning of the year	3,887,352	5,728,443	5,537,165
Additions	113,258	68,118	70,963
Loss on asset impairment	(58,595)	(17,162)	(191,490)
Properties reclassified to discontinued operations			341,024
Disposals	(1,085,125)	(1,892,047)	(29,219)
Balance at the end of the year	$ 2,856,890	$ 3,887,352	$ 5,728,443