Term Loan and Line of Credit (Details) - USD ($)	12 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2014	Dec. 02, 2014
Line of Credit Facility [Line Items]
Amount outstanding	$ 135,000,000
Current portion of long-term debt	15,000,000	$ 9,375,000
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Term loan				$ 150,000,000
Unsecured credit facility				150,000,000
Additional borrowing capacity available				75,000,000
Principal payments for years one and two	1,900,000
Principal payments for years three and four	3,800,000
Principal payments for years five and thereafter	$ 5,600,000
Average interest rate during period (as a percent)	2.22%
Interest rate at end period (as a percent)	2.31%
Debt issuance cost	$ 1,800,000
Amortization of debt issuance costs	400,000	$ 400,000	$ 100,000
Swing Line Loans [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Unsecured credit facility				25,000,000.0
Letter of Credit [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Unsecured credit facility				25,000,000.0
Line of credit facility outstanding amount	500,000
Revolving Credit Facility [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of credit facility outstanding amount	0
Term loan [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Term loan				$ 150,000,000
Amount outstanding	135,000,000
Current portion of long-term debt	$ 15,000,000