Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Comprehensive income (loss)
Net income	$ 12,138	$ 73	$ 17,804	$ 4,237
Unrealized gain (loss) on foreign currency translation, net of tax	(732)	(559)	(113)	1,514
Unrealized loss on derivative contracts, net of tax		(9)		(13)
Comprehensive income (loss)	$ 11,406	$ (495)	$ 17,691	$ 5,738