Recent Transactions (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Sep. 27, 2017
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 0.0	$ 180.6
Goodwill	1,856.5		$ 1,881.8
Sevcon, Inc [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				100.00%
Payments to Acquire Businesses, Net of Cash Acquired			185.7
Business Combination, Consideration Transferred, Other			26.6
Business Combination, Consideration Transferred			$ 5.1
Receivables, net				$ 15.9
Inventories, net				16.7
Other current assets				2.8
Property, plant and equipment, net				7.3
Goodwill				127.6
Other intangible assets				70.7
Deferred tax liabilities				(9.2)
Income taxes payable				(0.7)
Other assets and liabilities				(2.9)
Accounts payable and accrued expenses				(24.5)
Total consideration, net of cash acquired				203.7
Assumed retirement-related liabilities				18.0
Goodwill, Purchase Accounting Adjustments	$ (6.0)
Customer Relationships [Member] | Sevcon, Inc [Member]
Business Acquisition [Line Items]
Other intangible assets				17.7
Developed Technology Rights [Member] | Sevcon, Inc [Member]
Business Acquisition [Line Items]
Other intangible assets				48.8
Trade Names [Member] | Sevcon, Inc [Member]
Business Acquisition [Line Items]
Other intangible assets				$ 4.2
Minimum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	7 years
Maximum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	20 years