Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2013 7-5/8% Senior secured notes, due April 2019	Sep. 30, 2012 7-5/8% Senior secured notes, due April 2019	Mar. 31, 2011 7-5/8% Senior secured notes, due April 2019	Jun. 30, 2013 Convertible senior subordinated notes	Sep. 30, 2012 Convertible senior subordinated notes	Jun. 30, 2013 2.50% Convertible senior subordinated notes due February 2014	Mar. 31, 2013 2.50% Convertible senior subordinated notes due February 2014	Sep. 30, 2012 2.50% Convertible senior subordinated notes due February 2014	Jun. 30, 2012 2.50% Convertible senior subordinated notes due February 2014	Dec. 31, 2011 2.50% Convertible senior subordinated notes due February 2014	Jun. 30, 2013 8.75% Convertible senior subordinated notes due February 2016	Sep. 30, 2012 8.75% Convertible senior subordinated notes due February 2016	Jun. 30, 2012 8.75% Convertible senior subordinated notes due February 2016	Jun. 30, 2012 16% Convertible senior subordinated notes due 2016	Jun. 30, 2012 14.75% Convertible senior subordinated notes due 2014	Mar. 31, 2012 14.75% Convertible senior subordinated notes due 2014
Long-term debt
Debt instrument, face amount	$ 465,400	$ 504,900						$ 15,566		$ 55,077			$ 49,791	$ 49,791
Carrying amount of long-term debt, net of discounts	464,470	500,539	400,000	400,000		64,470	100,539	15,090		51,278			49,380	49,261
Less current portion	(15,090)	0
Long-term debt	$ 449,380	$ 500,539
Interest rate on long-term debt (as a percent)			7.625%	7.625%	7.625%			2.50%	2.50%	2.50%	2.50%	2.50%	8.75%	8.75%	8.75%	16.00%	14.75%	14.75%