Borrowings - Schedule of Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012	Jul. 31, 2012
Debt Instrument [Line Items]
Unamortized debt discounts	$ (2,944)	$ (3,082)
Long-term debt	1,496,951	1,498,198
Senior Notes
Debt Instrument [Line Items]
Unamortized debt discounts	(2,944)	(3,082)
Long-term debt	1,199,344	1,201,067
Senior Notes | 6 7/8% Senior Notes Maturing July 2015
Debt Instrument [Line Items]
Debt instrument stated interest rate (percent)	6.875%	6.875%
Senior notes	172,454	172,454
Senior Notes | 8 1/8% Senior Notes Maturing June 2016
Debt Instrument [Line Items]
Debt instrument stated interest rate (percent)	8.125%	8.125%
Senior notes	172,879	172,879
Senior Notes | 12% Senior Secured Notes Maturing October 2017
Debt Instrument [Line Items]
Debt instrument stated interest rate (percent)			12.00%
Long-term debt			250,000
Senior Notes | 6 5/8% Senior Secured Notes
Debt Instrument [Line Items]
Debt instrument stated interest rate (percent)	6.625%	6.625%	6.625%
Senior notes	300,000	300,000
Senior Notes | 9 1/8% Senior Notes Maturing June 2018
Debt Instrument [Line Items]
Debt instrument stated interest rate (percent)	9.125%	9.125%
Senior notes	300,000	300,000
Senior Notes | 9 1/8% Senior Notes Maturing May 2019
Debt Instrument [Line Items]
Debt instrument stated interest rate (percent)	9.125%	9.125%
Senior notes	235,000	235,000
Senior Notes | TEU Senior Amortizing Notes
Debt Instrument [Line Items]
Senior notes	239	316
Senior Notes | TEU Senior Amortizing Notes
Debt Instrument [Line Items]
Senior notes	21,716	23,500
Convertible Subordinated Debt
Debt Instrument [Line Items]
Long-term debt	9,402	9,402
Junior Subordinated Notes
Debt Instrument [Line Items]
Debt instrument stated interest rate (percent)	7.987%
Unamortized debt discounts	48,700
Long-term debt	52,120	51,603
Cash Secured Loan
Debt Instrument [Line Items]
Long-term debt	227,368	227,368
Other Secured Notes Payable
Debt Instrument [Line Items]
Long-term debt	$ 8,717	$ 8,758