Stockholders' Equity (Schedule of Stockholders Equity) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended					9 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011	Jun. 30, 2012 Common Stock	Sep. 30, 2011 Common Stock	Jun. 30, 2012 Additional Paid-In Capital	Jun. 30, 2012 Acculated Deficit	Jun. 30, 2012 Accumulated Other Comprehensive Income (Loss)	Jun. 30, 2012 Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at September 30, 2011				$ 235,246	[1]		$ 3	$ 3	$ 321,131	$ (87,328)	$ (1,252)	$ 2,692
Net income	3,147		8,095	10,513		21,067				10,528		(15)
Change in cumulative translation adjustment, net of tax	(1,176)		1,757	1,872		6,516					1,872
Change in unrealized losses on investments, net of tax	(314)		(139)	(324)		11					(324)
Change in retirement plan obligations, net of tax	(24)		(15)	(71)		(45)					26
Shares issued under equity compensation plans									4,338
Stock-based compensation									3,730
RSUs withheld for statutory withholding taxes				464					(464)
Change in noncontrolling interest in Wintram		1,400							9			62
Acquisition of noncontrolling interest in Wintram		2,400		2,370		0			(1,012)			(1,358)
Balance at June 30, 2012	$ 252,638			$ 252,638			$ 3	$ 3	$ 327,732	$ (76,800)	$ 322	$ 1,381

[1] Derived from audited financial statements.