Long-Term Debt (Details) (USD $)	1 Months Ended	9 Months Ended			1 Months Ended	9 Months Ended			9 Months Ended				9 Months Ended		1 Months Ended			9 Months Ended					1 Months Ended
	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Sep. 30, 2011	Dec. 31, 2011 Term loan B-1	Jun. 30, 2012 Term loan B-1	Sep. 30, 2011 Term loan B-1	Mar. 02, 2011 Term loan B-1	Jun. 30, 2012 Term loan B-1 Eurodollar (LIBOR)	Jun. 30, 2012 Term loan B-1 Base rate	Jun. 30, 2012 Revolving credit facility	Oct. 02, 2010 Revolving credit facility	Jun. 30, 2012 Revolving credit facility Eurodollar (LIBOR)	Jun. 30, 2012 Revolving credit facility Base rate	Oct. 31, 2010 Notes	Jun. 30, 2012 Notes	Sep. 30, 2011 Notes	Jun. 30, 2012 Notes On or after October 1, 2014	Jun. 30, 2012 Notes On or after October 1, 2015	Jun. 30, 2012 Notes On or after October 1, 2016 and thereafter	Jun. 30, 2012 Notes Prior to October 1, 2014	Oct. 02, 2010 Term loan A	Mar. 31, 2011 Term loan B	Oct. 02, 2010 Term loan B
Long-Term Debt
Long-term debt, gross		$ 2,157,500,000		$ 2,386,875,000		$ 1,507,500,000	$ 1,736,875,000									$ 650,000,000	$ 650,000,000
Less: current portion				17,500,000
Total long-term debt		2,157,500,000		2,369,375,000
Borrowing capacity											200,000,000	250,000,000
Face amount of debt								1,750,000,000														250,000,000		1,500,000,000
Reference rate for variable interest rate									Eurodollar (LIBOR)	Base rate			Eurodollar (LIBOR)	Base rate
Floor for reference rate (as a percent)									1.00%	2.00%
Margin rate over reference rate (as a percent)									3.25%	2.25%			3.25%	2.25%
Write off deferred financing cost	20,824,000	9,289,000	20,824,000		9,289,000
Write off premium																							2,394,000
Termination costs on interest rate swap contracts	1,525,000
Early principal payments					225,000,000
Unused line fee percentage											0.50%
Fronting fee Percentage											0.25%
Additional prepayment as a percentage of excess cash flows						50.00%
Debt issued															$ 650,000,000
Interest rate on debt instrument (as a percent)																9.00%
Redemption price as a percentage of principal amount																		104.50%	102.25%	100.00%	100.00%