Debt (Schedule of Note Related Interest Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Debt Instruments [Abstract]
Contractual interest expense	$ 1,797	$ 1,797
Amortization of note issuance costs	326	311
Amortization of note discount	2,846	2,647
Total interest expenses recognized	$ 4,969	$ 4,755
Effective interest rate of the liability component	7.73%	7.73%