Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Other comprehensive income (loss):
Effective portion of change in fair value of derivative instruments	$ 18,332	$ (26)	$ 21,704	$ (60)
Parent Company [Member]
Net income	(37,469)	(11,348)	(58,603)	(38,083)
Other comprehensive income (loss):
Amortization of loss on settlement of derivative instruments recognized in net income	2,366	2,366	4,733	4,733
Effective portion of change in fair value of derivative instruments	18,332	(26)	21,704	(60)
Less: reclassification adjustment for change in fair value of derivative instruments included in net income	8	7	16	9
Other comprehensive income	20,706	2,347	26,453	4,682
Comprehensive income	58,175	13,695	85,056	42,765
Less: comprehensive income (loss) attributable to noncontrolling interests:
Net income (loss) attributable to noncontrolling interests	(340)	(255)	(654)	128
Other comprehensive income (loss) attributable to noncontrolling interests	43	(6)	57	(16)
Comprehensive income (loss) attributable to noncontrolling interests	383	249	711	(144)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	57,792	13,446	84,345	42,909
Partnership Interest [Member]
Net income	(37,469)	(11,348)	(58,603)	(38,083)
Other comprehensive income (loss):
Amortization of loss on settlement of derivative instruments recognized in net income	2,366	2,366	4,733	4,733
Effective portion of change in fair value of derivative instruments	18,332	(26)	21,704	(60)
Less: reclassification adjustment for change in fair value of derivative instruments included in net income	8	7	16	9
Other comprehensive income	20,706	2,347	26,453	4,682
Comprehensive income	58,175	13,695	85,056	42,765
Less: comprehensive income (loss) attributable to noncontrolling interests:
Net income (loss) attributable to noncontrolling interests	(270)	(232)	(545)	(424)
Other comprehensive income (loss) attributable to noncontrolling interests	4	(10)	7	(25)
Comprehensive income (loss) attributable to noncontrolling interests	274	222	552	399
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	57,901	13,473	84,504	42,366
Noncontrolling Interests in Limited Partners' Interest in Consolidated Partnerships [Member] | Parent Company [Member]
Net income			(545)	(424)
Other comprehensive income (loss):
Other comprehensive income			7	(25)
Noncontrolling Interests in Limited Partners' Interest in Consolidated Partnerships [Member] | Partnership Interest [Member]
Net income			(545)	(424)
Total Noncontrolling Interests [Member] | Parent Company [Member]
Net income			$ (654)	$ 128