Fair Value Measurements (Fair Value Measurements within the Fair Value Hierarchy of the Financial Assets) (Details) - USD ($) $ in Thousands	May. 31, 2015	Nov. 30, 2014
Contingent consideration [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial liabilities	$ (504)	$ (1,717)
Contingent consideration [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial liabilities	0	0
Contingent consideration [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial liabilities	(209)	0
Contingent consideration [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial liabilities	(295)	(1,717)
Money market funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	21,845	67,893
Money market funds [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	21,845	67,893
Money market funds [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	0	0
Money market funds [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	0	0
State and municipal bond obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	33,101	20,186
State and municipal bond obligations [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	0	0
State and municipal bond obligations [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	33,101	20,186
State and municipal bond obligations [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	0	0
Foreign exchange contract [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets		(102)
Fair value of financial liabilities	(2,449)
Foreign exchange contract [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets		0
Fair value of financial liabilities	0
Foreign exchange contract [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets		(102)
Fair value of financial liabilities	(2,449)
Foreign exchange contract [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets		$ 0
Fair value of financial liabilities	$ 0