CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Class A Common Stock	Common Stock Class A Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Cumulative Dividends in Excess of Earnings	Total Stockholders’ Equity	Noncontrolling Interests
Beginning balance at Dec. 31, 2014	$ 1,476,421		$ 1,251	$ 2,281,932	$ 0	$ (836,044)	$ 1,447,139	$ 29,282
Beginning balance (in shares) at Dec. 31, 2014			125,087,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net	43,649		$ 18	43,631			43,649
Issuance of common stock, net (in shares)			1,800,000
Share-based award transactions, net	5,724		$ 2	5,722			5,724
Share-based award transactions, net (in shares)			202,000
Repurchase and cancellation of common stock	(1,667)		$ (1)	(1,666)			(1,667)
Repurchase and cancellation of common stock (in shares)			(62,000)
Redemption of noncontrolling interest and other	(813)			(813)			(813)
Dividends declared	(149,801)					(147,539)	(147,539)	(2,262)
Net income	33,445					32,931	32,931	514
Other comprehensive gain	0
Ending balance at Dec. 31, 2015	1,406,958		$ 1,270	2,328,806	0	(950,652)	1,379,424	27,534
Ending balance (in shares) at Dec. 31, 2015			127,027,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net	417,163		$ 141	417,022			417,163
Issuance of common stock, net (in shares)			14,138,000
Issuance of operating partnership units in connection with an acquisition	74,460							74,460
Share-based award transactions, net	7,071		$ 4	7,067			7,071
Share-based award transactions, net (in shares)			391,000
Repurchase and cancellation of common stock	(2,642)		$ (1)	(2,641)			(2,642)
Repurchase and cancellation of common stock (in shares)			(94,000)
Redemption of noncontrolling interest and other	(1,142)		$ 3	4,564			4,567	(5,709)
Redemption of noncontrolling interest and other (in shares)			257,000
Dividends declared	(168,678)					(164,221)	(164,221)	(4,457)
Net income	47,227					45,912	45,912	1,315
Other comprehensive gain	0
Ending balance at Dec. 31, 2016	1,780,417		$ 1,417	2,754,818	0	(1,068,961)	1,687,274	93,143
Ending balance (in shares) at Dec. 31, 2016		141,719,134	141,719,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net	1,746,956		$ 628	1,746,328			1,746,956
Issuance of common stock, net (in shares)			62,823,000
Issuance of operating partnership units in connection with an acquisition	1,125							1,125
Share-based award transactions, net	6,870		$ 3	6,867			6,870
Share-based award transactions, net (in shares)			230,000
Repurchase and cancellation of common stock	(3,413)		$ (1)	(3,412)			(3,413)
Repurchase and cancellation of common stock (in shares)			(116,000)
Redemption of noncontrolling interest and other	(2,014)		$ 2	3,927			3,929	(5,943)
Redemption of noncontrolling interest and other (in shares)			236,000
Dividends declared	(232,227)					(227,024)	(227,024)	(5,203)
Net income	65,454					63,916	63,916	1,538
Other comprehensive gain	280				274		274	6
Ending balance at Dec. 31, 2017	$ 3,363,448		$ 2,049	$ 4,508,528	$ 274	$ (1,232,069)	$ 3,278,782	$ 84,666
Ending balance (in shares) at Dec. 31, 2017		204,892,118	204,892,000