Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Consolidated Statements Of Comprehensive Income [Abstract]
Net Income	$ 84,788	$ 114,959	$ 110,743	$ 106,540
Other Comprehensive (Loss) Income
Change in Fair Value of Derivative Instruments	(1,179)	(124)	(959)	(540)
Less: Reclassification Adjustment for Change in Fair Value of Derivative Instruments Included in Net Income	(130)	140	(280)	319
Total Other Comprehensive (Loss) Income	(1,309)	16	(1,239)	(221)
Comprehensive Income	83,479	114,975	109,504	106,319
Less: Comprehensive Income Attributable to Noncontrolling Interests	(1,117)	(4,748)	(5,865)	(4,061)
Less: Preferred Distributions	(6,042)	(4,000)	(12,084)	(7,589)
Less: Extinguishment of Issuance Costs Upon Redemption of Series B Preferred Shares		(4,021)		(4,021)
Comprehensive Income Attributable to Common Shareholders	$ 76,320	$ 102,206	$ 91,555	$ 90,648