Fair Value Measurements (Fair Value Measurements within the Fair Value Hierarchy of the Financial Assets) (Details) (USD $) | Aug. 31, 2013 | Nov. 30, 2012 |
In Thousands, unless otherwise specified |
Contingent consideration [Member] | Total Fair Value [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial liabilities | $383 | |
Contingent consideration [Member] | Level 1 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial liabilities | 0 | |
Contingent consideration [Member] | Level 2 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial liabilities | 0 | |
Contingent consideration [Member] | Level 3 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial liabilities | 383 | |
Money market funds [Member] | Total Fair Value [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 58,914 | 125,591 |
Money market funds [Member] | Level 1 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 58,914 | 125,591 |
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] | Total Fair Value [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 26,640 | 50,818 |
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 | 26,640 | 50,818 |
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 |
Auction rate securities - municipal bonds [Member] | Total Fair Value [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 23,707 | 23,420 |
Auction rate securities - municipal bonds [Member] | Level 1 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 0 | 0 |
Auction rate securities - municipal bonds [Member] | Level 2 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 0 | 0 |
Auction rate securities - municipal bonds [Member] | Level 3 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 23,707 | 23,420 |
Auction rate securities - student loans [Member] | Total Fair Value [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 2,866 | 2,901 |
Auction rate securities - student loans [Member] | Level 1 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 0 | 0 |
Auction rate securities - student loans [Member] | Level 2 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 0 | 0 |
Auction rate securities - student loans [Member] | Level 3 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | 2,866 | 2,901 |
Corporate bonds [Member] | Total Fair Value [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | | 2,607 |
Corporate bonds [Member] | Level 1 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | | 0 |
Corporate bonds [Member] | Level 2 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | | 2,607 |
Corporate bonds [Member] | Level 3 [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | | 0 |
Foreign exchange contract [Member] | Total Fair Value [Member] | | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | | |
Fair value of financial assets | -87 | -186 |
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 | 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 | -87 | -186 |
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 | $0 |