Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016
Pension Benefits [Member]
Components of net periodic benefit cost (income) [Abstract]
Service cost	$ 35	$ 195
Interest cost	1,665	1,975
Expected return on plan assets	(2,182)	(2,466)
Amortization of net (gain) loss	556	774
Net periodic benefit income	74	478
Other Benefits [Member]
Components of net periodic benefit cost (income) [Abstract]
Service cost	56	62
Interest cost	149	156
Amortization of prior service credit	(225)	(224)
Amortization of net (gain) loss	(5)	2
Net periodic benefit income	$ (25)	$ (4)