Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other comprehensive income (loss):
Effective portion of change in fair value of derivative instruments	$ 521	$ (25)	$ 22,225	$ (85)
Parent Company [Member]
Net income	(40,664)	(19,820)	(99,268)	(57,903)
Other comprehensive income (loss):
Amortization of loss on settlement of derivative instruments recognized in net income	2,367	2,366	7,099	7,099
Effective portion of change in fair value of derivative instruments	521	(25)	22,225	(85)
Less: reclassification adjustment for change in fair value of derivative instruments included in net income	8	8	24	17
Other comprehensive income	2,896	2,349	29,348	7,031
Comprehensive income	43,560	22,169	128,616	64,934
Less: comprehensive income (loss) attributable to noncontrolling interests:
Net income (loss) attributable to noncontrolling interests	(400)	(251)	(1,055)	(123)
Other comprehensive income (loss) attributable to noncontrolling interests	6	(4)	63	(20)
Comprehensive income (loss) attributable to noncontrolling interests	406	247	1,118	103
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	43,154	21,922	127,498	64,831
Partnership Interest [Member]
Net income	(40,664)	(19,820)	(99,268)	(57,903)
Other comprehensive income (loss):
Amortization of loss on settlement of derivative instruments recognized in net income	2,367	2,366	7,099	7,099
Effective portion of change in fair value of derivative instruments	521	(25)	22,225	(85)
Less: reclassification adjustment for change in fair value of derivative instruments included in net income	8	8	24	17
Other comprehensive income	2,896	2,349	29,348	7,031
Comprehensive income	43,560	22,169	128,616	64,934
Less: comprehensive income (loss) attributable to noncontrolling interests:
Net income (loss) attributable to noncontrolling interests	(327)	(212)	(872)	(636)
Other comprehensive income (loss) attributable to noncontrolling interests	1	(9)	8	(34)
Comprehensive income (loss) attributable to noncontrolling interests	328	203	880	602
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	43,232	21,966	127,736	64,332
Noncontrolling Interests in Limited Partners' Interest in Consolidated Partnerships [Member] | Parent Company [Member]
Net income			(872)	(636)
Other comprehensive income (loss):
Other comprehensive income			8	(34)
Noncontrolling Interests in Limited Partners' Interest in Consolidated Partnerships [Member] | Partnership Interest [Member]
Net income			(872)	(636)
Total Noncontrolling Interests [Member] | Parent Company [Member]
Net income			$ (1,055)	$ (123)