Nature of Business and Summary of Significant Accounting Policies (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	$ 406,629	$ 522,464	$ 543,245
Total other comprehensive income (loss), net of tax	9,562	(3,933)	(10,902)
Balance, end of year	376,084	406,629	522,464
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	(28,425)	(24,582)
Other comprehensive loss before reclassifications	9,655	(3,843)
Total other comprehensive income (loss), net of tax	9,655	(3,843)
Balance, end of year	(18,770)	(28,425)	(24,582)
Unrealized Gains (Losses) on Investments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	(136)	(46)
Other comprehensive loss before reclassifications	(93)	(90)
Total other comprehensive income (loss), net of tax	(93)	(90)
Balance, end of year	(229)	(136)	(46)
Total [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	(28,561)	(24,628)	(13,726)
Other comprehensive loss before reclassifications	9,562	(3,933)
Total other comprehensive income (loss), net of tax	9,562	(3,933)	(10,902)
Balance, end of year	$ (18,999)	$ (28,561)	$ (24,628)