Business Acquisitions Business Acquisitions - Narrative (Details) - USD ($)			3 Months Ended		12 Months Ended
	Oct. 13, 2016	Oct. 12, 2016	Apr. 02, 2017	Apr. 03, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Net income			$ 4,773,000	$ 3,872,000
Goodwill, Purchase Accounting Adjustments			1.5
Net revenues			145,208,000	150,798,000
Operating Income (Loss)			7,354,000	$ 5,495,000
Downstream [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross		$ 195,000,000
Business acquisition, net of cash acquired	$ 198,000,000
Business Combination, Contingent Consideration, Liability		15,000,000
Purchase price		216,034,000
Fair value of accounts receivables acquired		28,100,000
Contingent Consideration Classified as Equity, Fair Value Disclosure			9,700,000		$ 12,200,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Value of Instruments Classified in Shareholders' Equity			2,500,000
Net revenues			22,500,000
Operating Income (Loss)			1,500,000
Amortization of Intangible Assets			$ 1,200,000
Schroedahl [Member]
Business Acquisition [Line Items]
Acquisition-related costs					$ 100,000
Earn-Out Minimum Target [Member] | Downstream [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High		15,000,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low		7,500,000
Business Combination, Contingent Consideration, Liability		$ 0