Equity Award Plans (Details Textual) (USD $)	1 Months Ended	12 Months Ended				12 Months Ended			1 Months Ended		12 Months Ended
	Sep. 30, 2008	Sep. 30, 2012 Award	Sep. 30, 2011	Sep. 30, 2010	Dec. 09, 2007	Sep. 30, 2012 Maximum [Member]	Sep. 30, 2012 Minimum [Member]	Sep. 30, 2012 1987 Plan [Member]	Jan. 31, 2010 2005 Plan [Member] Executive	Sep. 30, 2008 2005 Plan [Member]	Sep. 30, 2012 2005 Plan [Member]	Sep. 30, 2011 2005 Plan [Member]	Sep. 30, 2010 2005 Plan [Member]	Sep. 30, 2012 2005 Plan [Member] Maximum [Member]	Sep. 30, 2012 2005 Plan [Member] Minimum [Member]	Sep. 30, 2012 Director Plan [Member]	Sep. 30, 2012 Executive [Member] RSUs [Member] Maximum [Member]	Sep. 30, 2012 Executive [Member] RSUs [Member] Minimum [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of equity award plans		3
Options to be issued								4,350,000			2,000,000
Share based compensation arrangement by share based payment award number of shares authorized to be issued as stock options																400,000
Common stock shares issued, restricted stock units under 2005 Plan											1,000,000
Common stock available for grant under the 2005 Plan											518,782
Shares issued in respect of restricted stock under the 2005 Plan											286,745
Exercise of stock options, net, shares		135,000									119,600	368,800	443,900
Aggregate exercise price		$ 107,000	$ 2,285,000	$ 1,369,000							$ 1,007,000	$ 2,428,000	$ 2,552,000
Common stock at an exercise price										$ 6.87
Closing price for share of Company's common stock										15.00
Common stock shares purchased									120,000	200,000
Weighted average fair value of stock options		$ 6.17	$ 9.69	$ 7.61
Repurchase of common stock, shares		30,849	128,646	87,326
Cumulative restricted stock units available for future declaration																	58,590	19,531
Cumulative operating income during performance period, fiscal 2012 through fiscal 2014, minimum		120,000,000
Cumulative operating income during performance period, fiscal 2012 through fiscal 2014, maximum		132,000,000
Exercise price									$ 11.89
Number of executive officers awarded performance-based RSUs									4
Net-share settled by company		51,041	109,926	220,359
Actual tax benefit realized for tax deductions from option exercised		573,000	3,617,000	1,671,000
Share-based payment award, vesting period						5 years	4 years
Share-based payment award, expiration period		10 years												5 years	1 year
Equity Awards Plans (Textual) [Abstract]
Options unavailable for grant upon expiration of 1987 Plan					521,354
Restricted stock, shares vested to non-employee director		4,000
Unrecognized compensation cost		5,164,000
Weighted-average period recognized compensation cost		1 year 7 months 6 days
Total intrinsic value of options exercised		1,544,000	9,659,000	4,452,000
Cash received from options		107,000	2,285,000	1,369,000
Payments for tax obligations to the tax authorities on exercise or vesting date		$ 597,000	$ 2,786,000	$ 960,000
Number of consecutive trading days, supplemental condition	30 days