Revenue from Contracts with Customers Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 1,704.3	$ 1,900.9	$ 3,423.5	$ 3,759.3
North America [Member]
Disaggregation of Revenue [Line Items]
Net sales	1,376.6	1,522.0	2,732.4	3,032.6
Asia [Member]
Disaggregation of Revenue [Line Items]
Net sales	142.9	190.4	303.7	345.7
Europe [Member]
Disaggregation of Revenue [Line Items]
Net sales	158.0	156.0	332.3	314.3
South America [Member]
Disaggregation of Revenue [Line Items]
Net sales	26.8	32.5	55.1	66.7
Driveline [Member]
Disaggregation of Revenue [Line Items]
Net sales	1,140.0	1,272.6	2,273.8	2,486.9
Driveline [Member] | North America [Member]
Disaggregation of Revenue [Line Items]
Net sales	888.3	985.2	1,741.4	1,946.4
Driveline [Member] | Asia [Member]
Disaggregation of Revenue [Line Items]
Net sales	135.0	177.9	288.3	320.9
Driveline [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Net sales	90.8	78.5	192.4	155.3
Driveline [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Net sales	25.9	31.0	51.7	64.3
Metal Forming [Member]
Disaggregation of Revenue [Line Items]
Net sales	377.4	418.6	765.5	852.9
Metal Forming [Member] | North America [Member]
Disaggregation of Revenue [Line Items]
Net sales	301.4	327.1	606.8	666.7
Metal Forming [Member] | Asia [Member]
Disaggregation of Revenue [Line Items]
Net sales	7.9	12.5	15.4	24.8
Metal Forming [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Net sales	67.2	77.5	139.9	159.0
Metal Forming [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Net sales	0.9	1.5	3.4	2.4
Casting [Member]
Disaggregation of Revenue [Line Items]
Net sales	186.9	209.7	384.2	419.5
Casting [Member] | North America [Member]
Disaggregation of Revenue [Line Items]
Net sales	186.9	209.7	384.2	419.5
Casting [Member] | Asia [Member]
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Casting [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Casting [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 0.0	$ 0.0	$ 0.0	$ 0.0