Term Loan and Line of Credit (Details) - USD ($)	12 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2015	Nov. 20, 2017	Dec. 02, 2014
Line of Credit Facility [Line Items]
Amount outstanding	$ 123,750,000
Current portion of long-term debt	5,819,000	$ 15,000,000
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Principal payments for years one and two	1,500,000
Principal payments for year three	2,300,000
Principal payments for year five	3,100,000
Principal payments thereafter	3,900,000
Debt issuance cost				$ 1,200,000
Unamortized debt issuance costs				700,000
Amortization of debt issuance costs	$ 400,000	$ 400,000	$ 400,000
Percentage of domestic subsidiaries capital stock guaranteeing obligation	100.00%
Percentage of foreign subsidiaries capital stock guaranteeing obligation	65.00%
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	$ 1,400,000			1,400,000
Revolving Credit Facility [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Unsecured credit facility				150,000,000
Additional borrowing capacity available				125,000,000
Line of credit facility outstanding amount	0			0
Term loan [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Term loan				$ 123,800,000
Amount outstanding	123,800,000
Current portion of long-term debt	$ 6,200,000
Line of Credit [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Average interest rate during period (as a percent)	2.76%
Interest rate at end period (as a percent)	2.88%
Minimum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Commitment fee on undrawn portion (as a percent)	0.25%
Minimum [Member] | Eurodollar [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.50%
Minimum [Member] | Base Rate [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	0.50%
Maximum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Commitment fee on undrawn portion (as a percent)	0.35%
Maximum [Member] | Eurodollar [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	2.00%
Maximum [Member] | Base Rate [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.00%