Revolving Credit Facilities (Details)		3 Months Ended
	Feb. 22, 2016 USD ($)	Mar. 31, 2018 USD ($)	Aug. 10, 2010 USD ($)
Line of Credit Facility [Line Items]
Maturity date		Sep. 25, 2019
Required ratio of indebtedness to net capital		3.00
Required interest coverage ratio		5.00
Letters of credit to be drawn		$ 800,000
Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate		1.25%
Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate		2.50%
Eurodollar [Member] | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate		0.25%
Eurodollar [Member] | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate		1.50%
Base Rate [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	110.00%
International
Line of Credit Facility [Line Items]
Revolving commitment amount	$ 5,000,000
Unused capacity		$ 4,200,000
North America
Line of Credit Facility [Line Items]
Unused capacity		$ 22,000,000
August 2010 Credit Facility Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving commitment amount			$ 175,000,000
Increase in aggregate commitment amount			$ 50,000,000