CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Total Stockholders’ Equity	Preferred Stock	Common Stock	Additional Paid-in Capital	Cumulative Distributions in Excess of Net Income	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2016			5,750,000	65,285,614
Balance at Dec. 31, 2016	$ 1,015,609	$ 1,015,574	$ 58	$ 653	$ 1,208,862	$ (192,201)	$ (1,798)	$ 35
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	39,327	39,343				39,343		(16)
Other comprehensive income	965	965					965
Amortization of stock-based compensation	4,848	4,848			4,848
Common stock issuance, net (in shares)				139,820
Common stock issuance, net	(2,814)	(2,814)		$ 1	(2,815)
Preferred dividends	(5,121)	(5,121)				(5,121)
Common dividends	(56,099)	(56,099)				(56,099)
Balance (in shares) at Jun. 30, 2017			5,750,000	65,425,434
Balance at Jun. 30, 2017	996,715	996,696	$ 58	$ 654	1,210,895	(214,078)	(833)	19
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of ASU 2017-12 adoption	0	0				(795)	795
Balance (in shares) at Dec. 31, 2017			5,750,000	178,255,843
Balance at Dec. 31, 2017	3,437,249	3,432,807	$ 58	$ 1,783	3,636,913	(217,236)	11,289	4,442
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	263,270	263,258				263,258		12
Other comprehensive income	12,328	12,328					12,328
Distributions to noncontrolling interests	(72)							(72)
Amortization of stock-based compensation	4,434	4,434			4,434
Preferred stock redemption			(5,750,000)
Preferred stock redemption	(143,750)	(143,750)	$ (58)		(138,191)	(5,501)
Common stock issuance, net (in shares)				27,747
Common stock issuance, net	(202)	(202)		$ 0	(202)
Preferred dividends	(4,267)	(4,267)				(4,267)
Common dividends	(161,065)	(161,065)				(161,065)
Balance (in shares) at Jun. 30, 2018			0	178,283,590
Balance at Jun. 30, 2018	$ 3,407,925	$ 3,403,543	$ 0	$ 1,783	$ 3,502,954	$ (125,606)	$ 24,412	$ 4,382