Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Distributions in Excess of Earnings	Non-controlling Interests	Series A Preferred Stock Preferred Stock	Series L Preferred Stock Preferred Stock
Beginning balance (in shares) at Dec. 31, 2016		84,048,081
Beginning balance at Dec. 31, 2016	$ 966,589	$ 84	$ 1,566,073	$ (509)	$ (599,971)	$ 912
Increase (Decrease) in Stockholders' Equity
Distributions to noncontrolling interests	(37)					(37)
Stock-based compensation expense (in shares)		9,585
Stock-based compensation expense	116		116
Share repurchase (in shares)		(26,181,818)
Share repurchase	(576,000)	$ (26)	(489,027)		(86,947)
Special cash dividends paid to certain common stockholders ($2.26 per share) (Note 11)	(4,872)				(4,872)
Common dividends	(32,854)				(32,854)
Issuance of Series A Preferred Warrants	55		55
Dividends to holders of Series A Preferred Stock	(241)				(241)
Reclassification of Series A Preferred Stock to permanent equity	0
Other comprehensive income	1,445			1,445
Net income	357,698				357,688	10
Ending balance (in shares) at Sep. 30, 2017		57,875,848
Ending balance at Sep. 30, 2017	711,899	$ 58	1,077,217	936	(367,197)	885
Increase (Decrease) in Stockholders' Equity
Other comprehensive income	333
Net income	72,391
Ending balance (in shares) at Sep. 30, 2017		57,875,848
Ending balance at Sep. 30, 2017	711,899	$ 58	1,077,217	936	(367,197)	885
Beginning balance (in shares) at Dec. 31, 2017		43,784,939					60,592	8,080,740
Beginning balance at Dec. 31, 2017	626,705	$ 44	792,631	1,631	(399,250)	890	$ 1,508	$ 229,251
Increase (Decrease) in Stockholders' Equity
Distributions to noncontrolling interests	(67)					(67)
Stock-based compensation expense (in shares)		10,134
Stock-based compensation expense	124		124
Common dividends	(16,421)				(16,421)
Issuance of Series A Preferred Warrants	62		62
Dividends to holders of Series A Preferred Stock	(1,924)				(1,924)
Reclassification of Series A Preferred Stock to permanent equity (in shares)							505,984
Reclassification of Series A Preferred Stock to permanent equity	11,517		(1,047)				$ 12,564
Redemption of Series A Preferred Stock (in shares)							(400)
Redemption of Series A Preferred Stock	(7)		3				$ (10)
Other comprehensive income	1,407			1,407
Net income	2,042				2,027	15
Ending balance (in shares) at Sep. 30, 2018		43,795,073					566,176	8,080,740
Ending balance at Sep. 30, 2018	623,438	$ 44	791,773	3,038	(415,568)	838	$ 14,062	$ 229,251
Increase (Decrease) in Stockholders' Equity
Other comprehensive income	(183)
Net income	(529)
Ending balance (in shares) at Sep. 30, 2018		43,795,073					566,176	8,080,740
Ending balance at Sep. 30, 2018	$ 623,438	$ 44	$ 791,773	$ 3,038	$ (415,568)	$ 838	$ 14,062	$ 229,251