Debt (Details) (USD $)							0 Months Ended	6 Months Ended		1 Months Ended	6 Months Ended	1 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 2011 term loan A	Dec. 31, 2012 2011 term loan A	Jun. 30, 2013 2011 term loan B	Dec. 31, 2012 2011 term loan B	Nov. 21, 2012 9.875% senior notes	Jun. 30, 2013 9.875% senior notes	Dec. 31, 2012 9.875% senior notes	Mar. 31, 2013 8.50% senior notes	Jun. 30, 2013 8.50% senior notes	Mar. 31, 2013 8.50% senior notes Prior to April 15, 2016	Mar. 31, 2013 8.50% senior notes Prior to April 15, 2017	Mar. 31, 2013 8.50% senior notes During the twelve months commencing April 15, 2017	Mar. 31, 2013 8.50% senior notes During the twelve months commencing April 15, 2018	Mar. 31, 2013 8.50% senior notes Period commencing April 15, 2019	Mar. 31, 2013 8.50% senior notes Maximum Prior to April 15, 2016	Jun. 30, 2013 Other	Dec. 31, 2012 Other
Debt instrument
Total debt	$ 2,606,100,000	$ 2,416,165,000	$ 656,566,000	$ 756,974,000	$ 978,178,000	$ 1,127,770,000		$ 496,656,000	$ 496,510,000		$ 450,000,000							$ 24,700,000	$ 34,911,000
Less current debt	(14,919,000)	(18,793,000)
Total long term debt	2,591,181,000	2,397,372,000
Weighted average stated interest rate (as a percent)			4.78%		5.75%			9.88%			8.50%
Debt agreements
Aggregate principal amount								500,000,000
Interest rate (as a percent)							9.875%	9.875%		8.50%	8.50%
Initial price of debt (as a percent)								99.302%
Debt issued							$ 500,000,000			$ 450,000,000
Aggregate principal of debt redeemed (as a percent)																	35.00%
Redemption price of debt instrument (as a percent)											101.00%	108.50%	100.00%	104.25%	102.125%	100.00%