Fair Value Measurements (Hierarchy of Financial Assets) (Details) - USD ($) $ in Thousands	Feb. 28, 2019	Nov. 30, 2018
Money market funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	$ 11,612	$ 3,810
Money market funds | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	11,612	3,810
Money market funds | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
Money market funds | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
State and municipal bond obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	14,348	19,423
State and municipal bond obligations | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
State and municipal bond obligations | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	14,348	19,423
State and municipal bond obligations | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
U.S. treasury bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	4,379	6,705
U.S. treasury bonds | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
U.S. treasury bonds | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	4,379	6,705
U.S. treasury bonds | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	8,215	8,259
Corporate bonds | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
Corporate bonds | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	8,215	8,259
Corporate bonds | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
Foreign exchange derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	322	(170)
Foreign exchange derivatives | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0	0
Foreign exchange derivatives | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	322	(170)
Foreign exchange derivatives | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	$ 0	$ 0