Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Parent Company [Member]
Net income	$ 26,735	$ 8,130
Other comprehensive income (loss):
Amortization of loss on settlement of derivative instruments recognized in net income	2,367	2,367
Effective portion of change in fair value of derivative instruments	(34)	0
Less reclassification adjustment for change in fair value of derivative instruments included in net income	3	0
Other comprehensive income	2,336	2,367
Comprehensive income	29,071	10,497
Less: comprehensive income (loss) attributable to noncontrolling interests:
Net (loss) income attributable to noncontrolling interests	(383)	1,026
Other comprehensive (loss) income attributable to noncontrolling interests	(10)	5
Comprehensive (loss) income attributable to noncontrolling interests	(393)	1,031
Comprehensive income attributable to the Company / Partnership	29,464	9,466
Partnership Interest [Member]
Net income	26,735	8,130
Other comprehensive income (loss):
Amortization of loss on settlement of derivative instruments recognized in net income	2,367	2,367
Effective portion of change in fair value of derivative instruments	(34)	0
Less reclassification adjustment for change in fair value of derivative instruments included in net income	3	0
Other comprehensive income	2,336	2,367
Comprehensive income	29,071	10,497
Less: comprehensive income (loss) attributable to noncontrolling interests:
Net (loss) income attributable to noncontrolling interests	192	82
Other comprehensive (loss) income attributable to noncontrolling interests	(15)	0
Comprehensive (loss) income attributable to noncontrolling interests	177	82
Comprehensive income attributable to the Company / Partnership	$ 28,894	$ 10,415