Debt and Capital Lease Obligations - Narrative (Details) - USD ($) $ in Thousands				6 Months Ended
		Dec. 06, 2016	Dec. 22, 2014	Jun. 30, 2018	Jun. 30, 2017	May 18, 2018	Dec. 31, 2017	Dec. 28, 2016
Line of Credit Facility [Line Items]
Leverage ratio				199.00%
Fixed charge coverage ratio				263.00%
Total debt and capital lease obligations				$ 239,478			$ 209,192
Revolving credit facility, balance outstanding	[1]			216,751			207,322
Capital lease obligations, total				3,957			2,854
Remaining borrowing capacity on line of credit				22,600
Letters of credit outstanding				1,300
Unamortized debt issuance cost				717			984
Fair value of debt				233,500			$ 203,200
Cash paid for interest on debt				$ 4,100	$ 3,600
Revolving Credit Facility
Line of Credit Facility [Line Items]
Commitment fee percentage on line of credit				0.35%
Revolving credit facility, balance outstanding				$ 151,100
Term Loan
Line of Credit Facility [Line Items]
Revolving credit facility, balance outstanding				$ 65,600
Brewster Revolver
Line of Credit Facility [Line Items]
Borrowing capacity on line of credit		$ 20,000				$ 30,000		$ 38,000
Maturity date		Dec. 28, 2018
Commitment fee percentage on line of credit				0.25%
Revolving credit facility, balance outstanding	[1]			$ 19,487
Remaining borrowing capacity on line of credit				$ 10,500
Amended and Restated Credit Agreement
Line of Credit Facility [Line Items]
Maturity date			Dec. 22, 2019
Amended and Restated Credit Agreement | Senior Credit Facility
Line of Credit Facility [Line Items]
Borrowing capacity on line of credit			$ 300,000
Amended and Restated Credit Agreement | Revolving Credit Facility
Line of Credit Facility [Line Items]
Borrowing capacity on line of credit			175,000
Additional borrowing capacity on line of credit			100,000
Line of Credit borrowings used to support letter of credit			40,000
Amended and Restated Credit Agreement | Term Loan
Line of Credit Facility [Line Items]
Borrowing capacity on line of credit			$ 125,000
Amendment No. 1
Line of Credit Facility [Line Items]
Maximum leverage ratio for acquisition				300.00%
Leverage ratio required for dividend or share activity				250.00%
Maximum leverage ratio for unsecured debt				300.00%
Annual share repurchase limit on leverage ratio basis				$ 20,000
Amendment No. 1 | Maximum
Line of Credit Facility [Line Items]
Leverage ratio				350.00%
Amendment No. 1 | Minimum
Line of Credit Facility [Line Items]
Fixed charge coverage ratio				175.00%
Top Tier Foreign Subsidiaries | Amended and Restated Credit Agreement
Line of Credit Facility [Line Items]
Percent of lenders security interest on capital stock foreign subsidiary			65.00%

[1] Represents the weighted-average interest rate in effect at the respective periods for the revolving credit facilities and term loan borrowings, including any applicable margin. The interest rates do not include amortization of debt issuance costs or commitment fees.