Recent Transactions (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Sep. 27, 2017
Business Acquisition [Line Items]
Goodwill	$ 1,858.1	$ 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			18.6
Other current assets			2.8
Property, plant and equipment, net			7.3
Goodwill			126.0
Other intangible assets			70.7
Deferred tax liabilities			(9.5)
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	$ (7.6)
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