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Segment Information - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 30, 2017 | Dec. 29, 2018 | Dec. 30, 2017 | Dec. 31, 2016
Revenue from External Customer [Line Items] |  |  |  |  |  |
Gain on sale of manufacturing equipment |  | $ 253 | $ 624 | [1] | $ 651 | [1]
Gain on sale of business |  | 0 | (1,491) |  | 0 |
Impairment charges | $ 1,100 | 0 | 1,466 | [1],[2] | 6,778 | [1],[2]
Insurance recovery |  | (3,681) | 0 | [2] | 0 | [2]
Gain on sale of assets, net |  | (253) | (1,491) | [1],[2] | 0 | [1],[2]
Operating Segments [Member] | Piping Systems [Member] |  |  |  |  |  |
Revenue from External Customer [Line Items] |  |  |  |  |  |
Gain on sale of real property |  | 1,400 |  |  |  |
Gain on sale of manufacturing equipment |  | 700 |  |  |  |
Gain on sale of business |  |  | (1,500) |  |  |
Impairment charges |  |  | 1,466 |  | 6,115 |
Insurance recovery |  | 0 |  |  |  |
Gain on sale of assets, net |  | (2,093) | (1,491) |  |  |
Operating Segments [Member] | Industrial Metals [Member] |  |  |  |  |  |
Revenue from External Customer [Line Items] |  |  |  |  |  |
Impairment charges |  |  | 0 |  | $ 663 |
Insurance recovery |  | (3,681) |  |  |  |
Gain on sale of assets, net |  | $ (1,301) | $ 0 |  |  |
[1] | The Consolidated Statements of Cash Flows for prior periods have been adjusted to reflect the adoption of ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. The Consolidated Statements of Cash Flows reflect 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.
[2] | The Consolidated Statements of Income for prior periods have been adjusted to reflect the adoption of ASU 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. The components of net periodic benefit cost (income) other than the service cost component are included in other income, net in the Consolidated Statements of Income. Refer to Note 1 for further discussion.

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- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228 + Details
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- Definition Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
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