Summary Of Significant Accounting Policies (Reconciliation Of Net Income To Taxable Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary Of Significant Accounting Policies [Abstract]
Net income	$ 47,664	$ 26,318	$ 47,078
Net income attributable to noncontrolling interest	(9,808)	(6,237)	(12,659)
Net loss of taxable REIT Subsidiary included in net income	4	54	38
Net loss of taxable VIE, including impairment of real property		821	1,244
Net income from REIT operations	37,860	20,956	35,701
Book depreciation and amortization	114,138	96,153	87,424
Tax depreciation and amortization	(117,822)	(96,158)	(86,594)
Gains/losses from capital transactions	(22)	(86)	(3,131)
Carrying value of mortgages	(575)	(322)	(2,095)
Book/tax difference on equity compensation	(3,928)	(1,770)	2,057
Amortization of debt discount	1,409	1,586	1,438
Property acquisition costs	2,551	2,188
Other book/tax differences, net	1,912	1,609	(1,042)
Adjusted taxable income subject to 90% REIT dividend requirement	$ 35,523	$ 24,156	$ 33,758