v3.7.0.1
Segment and Geographical Data - Performance of Operating Segments (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
Segment Reporting Information [Line Items]                      
External 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
Adjusted EBITDA                 493.0 538.2 478.6
Capital Expenditures                 194.5 226.3 156.4
Depreciation/Amortization                 221.3 229.8 210.8
Total Assets 3,190.5       3,157.6       3,190.5 3,157.6 3,203.4
Operating Segments [Member] | ASP HHI Holdings, Inc [Member]                      
Segment Reporting Information [Line Items]                      
External Sales                 834.9 984.8 968.5
Intersegment Sales                 8.1 8.9 9.0
Adjusted EBITDA                 161.2 199.8 193.5
Capital Expenditures                 55.9 69.9 61.6
Depreciation/Amortization                 77.0 79.1 76.9
Total Assets 850.8       905.5       850.8 905.5 944.1
Operating Segments [Member] | ASP MD Holdings, Inc [Member]                      
Segment Reporting Information [Line Items]                      
External Sales                 1,168.5 1,155.7 1,176.4
Intersegment Sales                 1.3 1.2 1.2
Adjusted EBITDA                 220.5 205.7 202.3
Capital Expenditures                 100.2 85.4 70.5
Depreciation/Amortization                 74.6 78.2 92.4
Total Assets 1,286.2       1,243.8       1,286.2 1,243.8 1,216.4
Operating Segments [Member] | ASP Grede Intermediate Holdings LLC [Member]                      
Segment Reporting Information [Line Items]                      
External Sales                 787.3 906.8 572.1
Intersegment Sales                 0.4 0.3  
Adjusted EBITDA                 111.3 132.7 82.8
Capital Expenditures                 36.8 69.0 24.3
Depreciation/Amortization                 69.2 72.4 41.5
Total Assets 945.5       954.6       945.5 954.6 982.0
Intersegment Eliminations [Member]                      
Segment Reporting Information [Line Items]                      
Intersegment Sales                 (9.8) (10.4) (10.2)
Capital Expenditures                 1.6 2.0  
Depreciation/Amortization                 0.5 0.1  
Total Assets $ 108.0       $ 53.7       $ 108.0 $ 53.7 $ 60.9