Reportable Segment Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Reconciliation of reportable segment operating income to consolidated income before income taxes
Operating income	$ 9,073	$ 28,864	$ 31,334	$ 43,217
Interest expense	24,185	26,409	49,083	52,864
Earnings from equity investments	(6,915)	(9,224)	(15,760)	(18,574)
Other	1,108	(876)	630	(1,870)
Net (loss) income before income taxes	(9,305)	12,555	(2,619)	10,797
Reported Segment
Reconciliation of reportable segment operating income to consolidated income before income taxes
Operating income	30,474	50,146	74,880	86,604
Unallocated corporate costs
Reconciliation of reportable segment operating income to consolidated income before income taxes
Operating income	30,474	50,146	74,880	86,604
Unallocated corporate costs	$ 21,401	$ 21,282	$ 43,546	$ 43,387