v3.7.0.1

Acquisitions - Schedule of Revenues and Earnings Included in the Unaudited Consolidated Statements of Operations (Detail) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 | Oct. 02, 2016 | Jul. 03, 2016 | Apr. 03, 2016 | Dec. 31, 2015 | Sep. 27, 2015 | Jun. 28, 2015 | Mar. 29, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Business Acquisition Pro Forma Information Nonrecurring Adjustment [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenues: Net sales | $ 646.6 | $ 676.2 | $ 728.4 | $ 739.5 | $ 735.3 | $ 746.6 | $ 800.2 | $ 765.2 | $ 2,790.7 | $ 3,047.3 | $ 2,717.0
Earnings: Income (loss) before tax |  |  |  |  |  |  |  |  | 135.3 | 173.9 | 54.2
ASP Grede Intermediate Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition Pro Forma Information Nonrecurring Adjustment [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenues: Net sales |  |  |  |  |  |  |  |  | 787.3 | 906.8 | 572.1
Earnings: Income (loss) before tax |  |  |  |  |  |  |  |  | $ 17.9 | $ 43.3 | $ (19.2)

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