Consolidated Statements Of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Balance, beginning of year at Nov. 30, 2011	$ 625,110	$ 618	$ 308,603	$ 327,542	$ (11,653)
Balance, beginning of year, shares at Nov. 30, 2011		61,789,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under employee stock purchase plan, shares		376,000
Issuance of stock under the employee stock purchase plan, value	5,654	4	5,650
Exercise of stock options, shares		1,488,000
Exercise of stock options, value	23,435	15	23,420
Vesting of restricted stock units, shares		625,000
Vesting of restricted stock units, value	6	6
Withholding tax payments related to net issuance of restricted stock units, shares		(189,000)
Withholding tax payments related to net issuance of restricted stock units, value	(4,155)	(2)	(4,153)
Tax benefit arising from employee stock purchase plan, stock options and restricted share activity	167	0	167
Stock-based compensation	28,233		28,233
Treasury stock repurchases and retirements, shares	(4,494,000)	(4,494,000)
Treasury stock repurchases and retirements, value	(88,384)	(45)	(62,183)	(26,156)
Net income	47,444			47,444
Other comprehensive income (losses)	889				889
Balance, end of year at Nov. 30, 2012	638,399	596	299,737	348,830	(10,764)
Balance, end of year, shares at Nov. 30, 2012		59,595,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under employee stock purchase plan, shares		281,000
Issuance of stock under the employee stock purchase plan, value	4,298	3	4,295
Exercise of stock options, shares		2,722,000
Exercise of stock options, value	50,466	27	50,439
Vesting of restricted stock units, shares		697,000
Vesting of restricted stock units, value	7	7
Withholding tax payments related to net issuance of restricted stock units, shares		(203,000)
Withholding tax payments related to net issuance of restricted stock units, value	(4,938)	(2)	(4,936)
Tax benefit arising from employee stock purchase plan, stock options and restricted share activity	(520)	0	(520)
Stock-based compensation	21,399		21,399
Treasury stock repurchases and retirements, shares	(11,579,000)	(11,579,000)
Treasury stock repurchases and retirements, value	(269,469)	(116)	(165,622)	(103,731)
Net income	74,907			74,907
Other comprehensive income (losses)	(895)				(895)
Balance, end of year at Nov. 30, 2013	513,654	515	204,792	320,006	(11,659)
Balance, end of year, shares at Nov. 30, 2013	51,512,595	51,513,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under employee stock purchase plan, shares		203,000
Issuance of stock under the employee stock purchase plan, value	3,613	2	3,611
Exercise of stock options, shares	690,000	690,000
Exercise of stock options, value	12,820	7	12,813
Vesting of restricted stock units, shares		866,000
Vesting of restricted stock units, value	9	9
Withholding tax payments related to net issuance of restricted stock units, shares		(289,000)
Withholding tax payments related to net issuance of restricted stock units, value	(6,607)	(3)	(6,604)
Tax benefit arising from employee stock purchase plan, stock options and restricted share activity	96	0	96
Stock-based compensation	24,873		24,873
Treasury stock repurchases and retirements, shares	(2,306,000)	(2,306,000)
Treasury stock repurchases and retirements, value	(52,604)	(23)	(30,310)	(22,271)
Net income	49,458			49,458
Other comprehensive income (losses)	(2,067)				(2,067)
Balance, end of year at Nov. 30, 2014	$ 543,245	$ 507	$ 209,271	$ 347,193	$ (13,726)
Balance, end of year, shares at Nov. 30, 2014	50,676,769	50,677,000