Long-Term Debt (Details 5) (USD $)	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Long-Term Debt
Interest expense	$ 42,900,000	$ 53,400,000	$ 127,000,000
Non-cash interest expense	5,841,000	14,184,000	20,069,000
Weighted average interest rate (as a percent)	7.70%	7.20%
Long-term debt
Debt instrument early repayment premium			62,600,000
11-3/8% senior secured notes
Long-term debt
Debt instrument early repayment premium			$ 59,000,000
Interest rate on long-term debt (as a percent)			11.375%