Statement of Shareholders' Equity (USD $) In Thousands	Total	Common Stock Member	Additional Paid In Capital Member	Accumulated Other Comprehensive Income Member	Retained Earnings Member
Balance as of at Sep. 30, 2009	$ 207,927	$ 122	$ 124,337		$ 83,468
Shares Balance as of at Sep. 30, 2009		12,196
Net income	33,440				33,440
Issuance of common stock (shares)		6
Issuance of common stock	248		248
Exercises of common stock options (shares)		199
Exercises of common stock options	403	2	401
Tax benefit of common stock exercises	3,611		3,611
Stock Awards Issued (shares)	56
Issuance of stock awards, net of forfeitures	1,079	1	1,078
Foreign currency translation	536			536
Other	(457)			(457)
Balance as of at Sep. 30, 2010	246,787	125	129,675	79	116,908
Shares Balance as of at Sep. 30, 2010		12,457
Net income	42,580				42,580
Issuance of common stock (shares)		6
Issuance of common stock	412		412
Exercises of common stock options (shares)		102
Exercises of common stock options	98	1	97
Tax benefit of common stock exercises	2,714		2,714
Stock Awards Issued (shares)		53
Issuance of stock awards, net of forfeitures	861		861
Foreign currency translation	(663)			(663)
Other	21			21
Balance as of at Sep. 30, 2011	292,810	126	133,759	(563)	159,488
Shares Balance as of at Sep. 30, 2011		12,618
Net income	53,477				53,477
Issuance of common stock (shares)		7
Issuance of common stock	562		562
Issuance of common stock for purchase of Micro (shares)		94
Issuance of common stock for purchase of Micro	7,159	1	7,158
Exercises of common stock options (shares)		15
Exercises of common stock options	154		154
Tax benefit of common stock exercises	895		895
Stock Awards Issued (shares)		58
Issuance of stock awards, net of forfeitures	2,140	1	2,139
Foreign currency translation	1,877			1,877
Other	228			228
Balance as of at Sep. 30, 2012	$ 359,302	$ 128	$ 144,667	$ 1,542	$ 212,965
Shares Balance as of at Sep. 30, 2012		12,792