Stockholders' Equity - Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Accumulated other comprehensive income (loss), net of tax, beginning of period	$ 23,642	$ 17,324	$ 17,866
Other comprehensive income before reclassifications	(1,104)	(2,604)	(518)
Amounts reclassified from accumulated other comprehensive income	66	8,922	(24)
Accumulated other comprehensive income (loss), net of tax, end of period	22,604	23,642	17,324
Currency Translation Adjustments
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Accumulated other comprehensive income (loss), net of tax, beginning of period	24,511	26,917	25,970
Other comprehensive income before reclassifications	(2,113)	(2,406)	947
Amounts reclassified from accumulated other comprehensive income	0	0	0
Accumulated other comprehensive income (loss), net of tax, end of period	22,398	24,511	26,917
Unrealized Gains (Losses) on Available-for-Sale Securities
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Accumulated other comprehensive income (loss), net of tax, beginning of period	201	(192)	253
Other comprehensive income before reclassifications	(114)	408	(421)
Amounts reclassified from accumulated other comprehensive income	(21)	(15)	(24)
Accumulated other comprehensive income (loss), net of tax, end of period	66	201	(192)
Unrealized Gains on Cash Flow Hedges
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Accumulated other comprehensive income (loss), net of tax, beginning of period	0	0	0
Other comprehensive income before reclassifications	14	0	0
Amounts reclassified from accumulated other comprehensive income	0	0	0
Accumulated other comprehensive income (loss), net of tax, end of period	14	0	0
Pension Liability Adjustments
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Accumulated other comprehensive income (loss), net of tax, beginning of period	(1,070)	(9,401)	(8,357)
Other comprehensive income before reclassifications	1,109	(606)	(1,044)
Amounts reclassified from accumulated other comprehensive income	87	8,937	0
Accumulated other comprehensive income (loss), net of tax, end of period	$ 126	$ (1,070)	$ (9,401)