Summary Of Significant Accounting Policies (Calculation Of Earnings Per Share) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Summary Of Significant Accounting Policies [Abstract]
Net income	$ 49,373	$ 102,359	$ 95,948	$ 173,884
Net (income) loss allocated to Preferred shareholders based upon distributions	(12,959)	(12,959)	(25,918)	(25,962)
Net (income) loss allocated to Noncontrolling interest - joint venture	(10)	383	(13)	819
Net (income) loss allocated to Restricted stock unit holders	(212)	(779)	(480)	(1,353)
Net income allocable to common shareholders and noncontrolling interests - common units	36,192	89,004	69,537	147,388
Net income allocation to noncontrolling interests - common units	(7,613)	(18,783)	(14,637)	(31,119)
Net income allocable to common shareholders	$ 28,579	$ 70,221	$ 54,900	$ 116,269
Weighted average common shares outstanding	27,426	27,322	27,400	27,294
Weighted average common partnership units outstanding	7,305	7,305	7,305	7,305
Total common share equivalents	34,731	34,627	34,705	34,599
Common partnership units as a percentage of common share equivalents	21.00%	21.10%	21.00%	21.10%
Net effect of dilutive stock compensation - based on treasury stock method using average market price	106	101	105	101
Diluted weighted average common shares outstanding	27,532	27,423	27,505	27,395