Accumulated Other Comprehensive Loss (Details) $ in Thousands	9 Months Ended
	Aug. 31, 2016 USD ($)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 1, 2015	$ 522,464
Balance, August 31, 2016	494,579
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 1, 2015	(24,582)
Other comprehensive loss before reclassifications, net of tax	485
Amounts reclassified from accumulated other comprehensive loss to realized losses included in earnings	256
Balance, August 31, 2016	(23,841)
Unrealized Gains (Losses) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 1, 2015	(46)
Other comprehensive loss before reclassifications, net of tax	27
Amounts reclassified from accumulated other comprehensive loss to realized losses included in earnings	0
Balance, August 31, 2016	(19)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 1, 2015	(24,628)
Other comprehensive loss before reclassifications, net of tax	512
Amounts reclassified from accumulated other comprehensive loss to realized losses included in earnings	256
Balance, August 31, 2016	$ (23,860)