Long-term Debt (Details 5) (USD $)	3 Months Ended		9 Months Ended			1 Months Ended	9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Sep. 30, 2011	Mar. 31, 2011 11-3/8% senior secured notes	Jun. 30, 2011 11-3/8% senior secured notes
Long-term Debt
Interest expense	$ 16,000,000	$ 13,400,000	$ 42,200,000	$ 113,100,000
Non-cash interest expense	6,800,000	2,600,000	12,687,000	17,111,000
Capitalized interest costs			100,000	100,000
Interest income	0	100,000	100,000	200,000
Weighted average interest rate (as a percent)	7.10%		7.10%		6.80%
Long-term debt
Debt instrument prepayment premium						$ 59,000,000	$ 59,000,000