Reporting Segments and Related Information (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Customer sales										$ 9,799.3	$ 9,071.0	$ 8,023.2
Net sales		$ 2,586.4	$ 2,416.2	$ 2,389.7	$ 2,407.0	$ 2,259.0	$ 2,214.2	$ 2,329.2	$ 2,268.6	9,799.3	9,071.0	8,023.2
Year-end assets		9,787.6				8,834.7				9,787.6	8,834.7	8,825.7
Depreciation and amortization										407.8	391.4	320.2
Long-lived asset expenditures	[1]									560.0	500.6	577.3
Operating Segments [Member]
Segment Reporting Information [Line Items]
Customer sales										9,799.3	9,071.0	8,023.2
Net sales										9,799.3	9,071.0	8,023.2
Year-end assets		8,636.7				7,347.0				8,636.7	7,347.0	7,702.9
Depreciation and amortization										379.7	366.4	297.2
Long-lived asset expenditures	[1]									547.1	481.5	554.2
Engine [Member]
Segment Reporting Information [Line Items]
Customer sales										6,009.0	5,547.3	5,466.5
Inter-segment sales										52.5	42.8	33.5
Net sales										6,061.5	5,590.1	5,500.0
Year-end assets		4,732.9				4,134.6				4,732.9	4,134.6	4,017.8
Depreciation and amortization										218.8	211.9	200.2
Long-lived asset expenditures	[1]									305.5	298.7	332.4
Drivetrain [Member]
Segment Reporting Information [Line Items]
Customer sales										3,790.3	3,523.7	2,556.7
Inter-segment sales
Net sales										3,790.3	3,523.7	2,556.7
Year-end assets		3,903.8				3,212.4				3,903.8	3,212.4	3,685.1
Depreciation and amortization										160.9	154.5	97.0
Long-lived asset expenditures	[1]									241.6	182.8	221.8
Inter-segment eliminations [Member]
Segment Reporting Information [Line Items]
Inter-segment sales										(52.5)	(42.8)	(33.5)
Net sales										(52.5)	(42.8)	(33.5)
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Year-end assets	[2]	$ 1,150.9				$ 1,487.7				1,150.9	1,487.7	1,122.8
Depreciation and amortization	[2]									28.1	25.0	23.0
Long-lived asset expenditures	[1],[2]									$ 12.9	$ 19.1	$ 23.1

[1] Long-lived asset expenditures include capital expenditures and tooling outlays.

[2] Corporate assets include investments and other long-term receivables and deferred income taxes.