Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 19,630	$ 46,648	$ 47,271
Addtitions for (reductions in) in tax positions related to current year	(1,620)	903	(1,624)
Additions for tax positions related to prior years	0	0	1,563
Reductions for tax positions of prior years	0	(27,181)	(252)
Settlements with taxing authorities	0	0	(310)
Lapse of statute of limitations	(546)	(740)	0
Balance at end of year	$ 17,464	$ 19,630	$ 46,648