Acquisitions and Dispositions - Dispositions (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended			12 Months Ended
	Jun. 21, 2017	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017		Dec. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss		$ (471)	$ 217	$ 17,860	$ 2,704
Gain on sale of business				$ 0	1,631	[1]
Mueller-Xingrong [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage	50.50%
Net sales							$ 67,300
Net loss							$ 9
Mueller-Xingrong [Member] | Disposed of by sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of interest in joint venture	$ 18,300
Assets disposed of	56,800
Liabilities disposed of	36,200
Cumulative translation gain as a result of sale	$ 3,800
Gain on sale of business			$ 1,600		$ 1,600

[1] The Condensed Consolidated Statement of Cash Flows for the six months ended July 1, 2017 has been adjusted to reflect the adoption of ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. The Condensed Consolidated Statements of Cash Flows reflects the changes during the periods in the total of cash, cash equivalents, and restricted cash. Therefore, restricted cash activity is included with cash when reconciling the beginning-of-period and end-of-period total amounts shown. Refer to Note 1 for further discussion.