Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Distributions In Excess of Earnings	Treasury Stock	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2014		97,581,598
Balance at Dec. 31, 2014	$ 1,359,816	$ 98	$ 1,824,381	$ 0	$ (460,623)	$ (4,901)	$ 861
Increase (Decrease) in Stockholders' Equity
Contributions from noncontrolling interests	110						110
Distributions to noncontrolling interests	(38)						(38)
Stock-based compensation expense (in shares)		8,000
Stock-based compensation expense	1,066		1,066
Common dividends	(64,042)				(64,042)
Other comprehensive income (loss)	(6,312)			(6,312)
Net income	12,955				12,950		5
Balance (in shares) at Sep. 30, 2015		97,589,598
Balance at Sep. 30, 2015	1,303,555	$ 98	1,825,447	(6,312)	(511,715)	$ (4,901)	938
Balance (in shares) at Dec. 31, 2015		97,589,598
Balance at Dec. 31, 2015	1,297,347	$ 98	1,820,451	(2,519)	(521,620)		937
Increase (Decrease) in Stockholders' Equity
Distributions to noncontrolling interests	(36)						(36)
Stock-based compensation expense (in shares)		10,176
Stock-based compensation expense	114		114
Issuance of shares pursuant to employment agreement (in shares)		76,423
Repurchase of common stock (in shares)		(13,628,116)
Repurchase of common stock	(290,134)	$ (14)	(254,547)		(35,573)
Common dividends	(58,930)				(58,930)
Other comprehensive income (loss)	(7,098)			(7,098)
Net income	36,926				36,917		9
Balance (in shares) at Sep. 30, 2016		84,048,081
Balance at Sep. 30, 2016	$ 978,189	$ 84	$ 1,566,018	$ (9,617)	$ (579,206)		$ 910