Recent Transactions (Details) $ / shares in Units, ₨ in Millions, $ in Millions			3 Months Ended			9 Months Ended		12 Months Ended
	Jan. 29, 2015 USD ($)	Jan. 29, 2015 INR (₨)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Nov. 10, 2015 USD ($) number_of_countries	Jul. 13, 2015 $ / shares
Business Acquisition [Line Items]
Proceeds from Divestiture of Businesses, Net of Cash Divested				$ 5.4
Noncontrolling Interest, Decrease from Deconsolidation				4.8
Aggregated estimated fair value of assets acquired and liabilities assumed
Goodwill				1,730.2		$ 1,730.2		$ 1,757.7
Cash paid, net of cash acquired						0.0	$ 12.6
Goodwill, purchase accounting adjustments						(7.2)
Proceeds from sale of business, net of cash divested						5.4	0.0
Gain on previously held equity interest				0.0	$ 0.0	0.0	10.8
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net				71.5		71.5
Disposal Group, Including Discontinued Operation, Inventory				91.2		91.2
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Current				30.5		30.5
Disposal Group, Including Discontinued Operation, Goodwill				21.3		21.3
Disposal Group, Including Discontinued Operation, Intangible Assets, Current				19.6		19.6
Disposal Group, Including Discontinued Operation, Other Assets, Current				44.2		44.2
Asset impairment expense				(106.5)	$ 0.0	(106.5)	$ 0.0
Assets held for sale				171.8		171.8		0.0
Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities, Current				76.7		76.7
Disposal Group, Including Discontinued Operation, Accrued Income Tax Payable, Current				0.2		0.2
DisposalGroupincludingDiscontinuedOperationsLong-termDebt				9.0		9.0
Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation, Current				3.6		3.6
Disposal Group, Including Discontinued Operation, Other Liabilities, Current				5.8		5.8
Liabilities held for sale				$ 95.3		$ 95.3		0.0
Remy International Inc.
Business Acquisition [Line Items]
Equity interest acquired									100.00%
Business acquisition, share price | $ / shares										$ 29.50
Business Combination, Consideration Transferred, Other								361.0
Number of countries in which entity operates | number_of_countries									10
Aggregated estimated fair value of assets acquired and liabilities assumed
Receivables, net									$ 222.8
Inventories, net									195.3
Property, plant and equipment, net									196.6
Goodwill									577.5
Other intangible assets, net of tax									412.6
Other assets and liabilities									(205.1)
Accounts payable and accrued expenses									(170.7)
Total consideration, net of cash acquired									1,229.0
Less: Assumed retirement-related liabilities									31.1
Less: Assumed debt									10.9
Cash paid, net of cash acquired								$ 1,187.0
Remy International Inc. | In Process Research and Development [Member]
Aggregated estimated fair value of assets acquired and liabilities assumed
Other intangible assets, net of tax									3.8
Remy International Inc. | Customer Relationships
Aggregated estimated fair value of assets acquired and liabilities assumed
Other intangible assets, net of tax									303.3
Remy International Inc. | Developed Technology Rights [Member]
Aggregated estimated fair value of assets acquired and liabilities assumed
Other intangible assets, net of tax									46.4
Remy International Inc. | Trade Names
Aggregated estimated fair value of assets acquired and liabilities assumed
Other intangible assets, net of tax									59.0
Remy International Inc. | Other Intangible Assets [Member]
Aggregated estimated fair value of assets acquired and liabilities assumed
Other intangible assets, net of tax									$ 0.1
BERU Diesel Start Systems Pvt. Ltd.
Business Acquisition [Line Items]
Equity interest acquired	51.00%
Aggregated estimated fair value of assets acquired and liabilities assumed
Cash paid, net of cash acquired	$ 12.6	₨ 783.1
Definite-lived intangible assets	11.2
Assumed liabilities	4.6
Nondeductible amount of goodwill	13.9
Assets acquired	$ 16.0
Equity interest acquired, step acquisition	100.00%
Minimum | Remy International Inc.
Aggregated estimated fair value of assets acquired and liabilities assumed
Weighted average useful life								5 years
Maximum | Remy International Inc.
Aggregated estimated fair value of assets acquired and liabilities assumed
Weighted average useful life								15 years
Subsequent Event [Member]
Aggregated estimated fair value of assets acquired and liabilities assumed
Proceeds from sale of business, net of cash divested			$ 80.0
Divgi-Warner [Member]
Business Acquisition [Line Items]
Noncontrolling Interest, Parent Ownership of Interests Sold				60.00%