Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Sales Revenue, Goods, Net	$ 2,694.0	$ 2,389.7	$ 5,478.3	$ 4,796.7
Contract with Customer, Liability, Current	11.9		11.9			$ 12.1
Contract with Customer, Liability, Noncurrent	19.3		19.3			21.9
Contract with Customer, Refund Liability, Current	10.9		10.9			18.4
Contract with Customer, Asset, Net	10.7		10.7		$ 9.4
Engine [Member]
Sales Revenue, Goods, Net	1,674.3	1,481.8	3,390.4	2,977.2
Drivetrain [Member]
Sales Revenue, Goods, Net	1,034.1	921.0	2,117.0	1,845.9
Europe [Member] | Consolidated Entities [Member]
Sales Revenue, Goods, Net	1,054.5	914.1	2,191.9	1,830.1
Europe [Member] | Engine [Member]
Sales Revenue, Goods, Net	806.6	685.2	1,652.8	1,364.3
Europe [Member] | Drivetrain [Member]
Sales Revenue, Goods, Net	247.9	228.9	539.1	465.8
Asia [Member] | Consolidated Entities [Member]
Sales Revenue, Goods, Net	767.5	618.1	1,525.9	1,262.0
Asia [Member] | Engine [Member]
Sales Revenue, Goods, Net	430.4	365.1	852.1	757.0
Asia [Member] | Drivetrain [Member]
Sales Revenue, Goods, Net	337.1	253.0	673.8	505.0
Other Foreign [Member] | Consolidated Entities [Member]
Sales Revenue, Goods, Net	38.8	32.7	77.6	60.9
Other Foreign [Member] | Engine [Member]
Sales Revenue, Goods, Net	31.1	25.3	62.7	46.8
Other Foreign [Member] | Drivetrain [Member]
Sales Revenue, Goods, Net	7.7	7.4	14.9	14.1
All Countries [Domain] | Consolidated Entities [Member]
Sales Revenue, Goods, Net	2,694.0	2,389.7	5,478.3	4,796.7
All Countries [Domain] | Engine [Member]
Sales Revenue, Goods, Net	1,659.9	1,468.6	3,361.1	2,950.7
All Countries [Domain] | Drivetrain [Member]
Sales Revenue, Goods, Net	1,034.1	921.1	2,117.2	1,846.0
North America [Member] | Consolidated Entities [Member]
Sales Revenue, Goods, Net	833.2	824.8	1,682.9	1,643.7
North America [Member] | Engine [Member]
Sales Revenue, Goods, Net	391.8	393.0	793.5	782.6
North America [Member] | Drivetrain [Member]
Sales Revenue, Goods, Net	441.4	$ 431.8	889.4	$ 861.1
Prepaid Expenses and Other Current Assets [Member]
Contract with Customer, Asset, Net	25.5		25.5			18.2
Other Noncurrent Assets [Member]
Contract with Customer, Asset, Net	$ 172.4		$ 172.4			$ 180.4
Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period			3 years
Capitalized contract costs, amortization period			3 years
Revenue, Performance Obligation, Description of Payment Terms			30
Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period			7 years
Capitalized contract costs, amortization period			7 years
Revenue, Performance Obligation, Description of Payment Terms			90