Fair Value Measurements (Fair Value Measurements within the Fair Value Hierarchy of the Financial Assets) (Details) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012
Contingent Consideration [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial liabilities	$ (388)
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	(388)
Money Market Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	54,513	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	54,513	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]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	31,102	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	31,102	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 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Percentage of par value received on investment	80.00%
Auction Rate Securities - Municipal Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	23,453	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	1,520	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	21,933	23,420
Auction Rate Securities - Student Loans [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	2,828	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	2,828	2,901
Corporate Bonds [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 Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	171	(186)
Foreign Exchange Derivatives [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 Derivatives [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	171	(186)
Foreign Exchange Derivatives [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of financial assets	$ 0	$ 0