Nature of Operations and Summary of Significant Accounting Policies - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Accounting Policies [Abstract]
Cash Paid for Interest	$ 4,268	$ 366
Cash Paid for Income Taxes, Net of Refunds	14,808	7,076
Non-Cash Investing Activities:
Estimated post-closing adjustment	237	0
Non-cash additions to property, plant and equipment	1,033	390
Non-Cash Financing Activities:
Issuance of Company common stock upon vesting of restricted stock units	3,264	2,814
Dividends declared but unpaid	$ 2,442	$ 2,311