Contingencies And Commitments (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended	18 Months Ended
	Jul. 02, 2017	Dec. 31, 2016	Jul. 02, 2017
Contingencies, Commitments And Guarantees [Line Items]
Environmental remediation costs	$ 1,400	$ 300	$ 1,700
Aggregate notional value standby letters of credit	$ 40,090		$ 40,090
Minimum [Member]
Contingencies, Commitments And Guarantees [Line Items]
Expiration period, minimum in months and maximum in years	1 month
Maximum [Member]
Contingencies, Commitments And Guarantees [Line Items]
Expiration period, minimum in months and maximum in years	5 years