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Financial Instruments - Change in Fair value (Details) - USD ($) $ in Millions |  |  |  | 3 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 30, 2016 | Feb. 26, 2016 | Nov. 30, 2015 | Apr. 02, 2017 | Dec. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2017 | Feb. 26, 2016 | Nov. 30, 2015
Watts Korea |  |  |  |  |  |  |  |  |
Reconciliation of changes in fair value of all financial assets and liabilities |  |  |  |  |  |  |  |  |
Balance at the ending of the period |  | $ 0.8 |  |  |  |  |  |  |
Liability recorded at acquisition date fair value |  | 0.8 |  |  |  |  |  | $ 0.8 |
Outstanding shares acquired (as a percent) | 10.00% |  |  |  |  |  |  | 50.00% |
Purchase price | $ 0.8 | $ 4.0 |  |  | $ 0.7 |  |  |  |
Aggregate ownership percentage |  |  |  |  |  |  | 100.00% |  |
Apex |  |  |  |  |  |  |  |  |
Reconciliation of changes in fair value of all financial assets and liabilities |  |  |  |  |  |  |  |  |
Balance at the ending of the period |  |  |  |  |  | $ 2.9 |  |  |
Liability recorded at acquisition date fair value |  |  |  |  |  | 2.9 | $ 2.9 |  |
Shares remaining to be acquired |  |  |  |  |  |  | 10.00% |  | 20.00%
Outstanding shares acquired (as a percent) |  |  |  | 10.00% |  |  |  |  | 80.00%
Purchase price |  |  | $ 20.4 | $ 2.9 |  |  |  |  |
Aggregate ownership percentage |  |  |  | 90.00% |  |  | 90.00% |  |
Redeemable financial instrument |  |  |  |  |  |  |  |  |
Reconciliation of changes in fair value of all financial assets and liabilities |  |  |  |  |  |  |  |  |
Balance at the beginning of the period |  |  |  | $ 5.8 |  | 5.8 |  |  |
Settlements |  |  |  |  |  | (2.9) |  |  |
Balance at the ending of the period |  |  |  |  | 5.8 | 2.9 |  |  |
Liability recorded at acquisition date fair value |  |  |  | $ 5.8 | $ 5.8 | $ 5.8 | $ 2.9 |  |
Redeemable financial instrument | Apex |  |  |  |  |  |  |  |  |
Reconciliation of changes in fair value of all financial assets and liabilities |  |  |  |  |  |  |  |  |
Balance at the ending of the period |  |  | 5.5 |  |  |  |  |  |
Liability recorded at acquisition date fair value |  |  | $ 5.5 |  |  |  |  |  | $ 5.5

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- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463 + Details
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- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477 + Details
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- Definition Percentage of voting equity interests acquired in a business combination achieved in stages, including equity interests in the acquiree held by the acquirer immediately before the acquisition date and acquired at the acquisition date. + References No definition available. + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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