Schedule III - Real Estate and Accumulated Depreciation (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in total real estate assets
Balance, beginning of period	$ 6,705,982	$ 5,916,933	$ 3,923,624
Acquisitions and building improvements	1,597,392	814,235	2,004,742
Dispositions	(77,916)	(11,555)	(11,433)
Write-offs	(5,922)	(13,631)	0
Impairment	(4,970)	0	0
Balance, end of period	$ 8,214,566	$ 6,705,982	$ 5,916,933