Schedule III - Real Estate and Accumulated Depreciation (Details 2) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Total real estate held for investment, beginning of year		$ 6,328,146	$ 6,057,932	$ 5,264,947
Acquisitions		460,957	139,123	340,296
Improvements, etc.		386,836	536,411	588,166
Total additions during period		847,793	675,534	928,462
Cost of real estate sold		(68,200)	(231,984)	(113,416)
Properties held for sale		(13,193)	(160,074)	(14,700)
Other	[1]	(33,792)	(13,262)	(7,361)
Total deductions during period		(115,185)	(405,320)	(135,477)
Total real estate held for investment, end of year		$ 7,060,754	$ 6,328,146	$ 6,057,932

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