Stockholders’ Equity (Narrative) (Details) (USD $)	0 Months Ended		1 Months Ended		3 Months Ended	12 Months Ended					2 Months Ended	12 Months Ended				12 Months Ended
	Aug. 15, 2012	Oct. 13, 2011	Aug. 31, 2013	Jan. 31, 2013	Aug. 31, 2012	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2013 Treasury Stock [Member]	Aug. 31, 2012 Treasury Stock [Member]	Oct. 25, 2013 Subsequent Event [Member]	Aug. 31, 2013 Restricted Stock Units [Member]	Aug. 31, 2012 Restricted Stock Units [Member]	Aug. 31, 2011 Restricted Stock Units [Member]	Aug. 31, 2013 2006 Plan [Member]	Aug. 31, 2013 Employee Stock Option [Member]	Aug. 31, 2013 Board of Director Stock Option [Member]	Aug. 31, 2013 Minimum [Member] 2006 Plan [Member]	Aug. 31, 2013 Maximum [Member] 2006 Plan [Member]	Aug. 31, 2013 Employee Stock [Member]	Aug. 31, 2013 Employee Stock [Member] Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation percentage																					10.00%
Stock’s fair market value																					$ 25,000
Discount price percentage																				15.00%
Shares available for grant															1,700,000					900,000
Stock-based compensation cost recognized						3,630,000	4,295,000	5,644,000
Excess tax benefits						1,200,000	1,200,000	1,300,000
Unvested unrecognized compensation cost			4,600,000			4,600,000
Unvested unrecognized compensation cost, period						1 year 10 months 24 days
Contractual term																		7 years	10 years
Vesting period												3 years				3 years	1 year
Weighted average fair value of stock options granted						$ 4.69	$ 2.88	$ 4.63
Proceeds from exercise of stock options						16,343,000	280,000	2,130,000
Total intrinsic value of options exercised						3,800,000	100,000	800,000
Aggregate fair value of restricted stock												900,000	500,000	700,000
Shares repurchase authorized amount	40,000,000	30,000,000	40,000,000	55,000,000
Shares acquired through stock repurchase program					100,000				3,332,000	4,157,000	250,000
Total cost for shares acquired through stock repurchase program					$ 1,100,000	$ 35,480,000	$ 31,102,000		$ 35,480,000	$ 31,102,000	$ 4,500,000