Business Combinations - Schedule of Net Assets Acquired (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Sep. 20, 2017
Net assets acquired:
Goodwill	$ 472.0	$ 468.8
Hudson
Net assets acquired:
Goodwill			$ 238.3
Identifiable intangible assets			211.0
Accounts receivable			34.6
Property, plant and equipment			29.4
Inventories			26.5
Other current assets			8.1
Unbilled contract revenue			4.9
Other assets			2.9
Prepaid expenses			0.9
Deferred tax liabilities			(87.6)
Accounts payable			(21.2)
Customer advances and billings in excess of contract revenue			(17.4)
Accrued salaries, wages and benefits			(4.4)
Other current liabilities			(3.8)
Other long-term liabilities			(1.9)
Current portion of warranty reserve			(0.8)
Net assets acquired			$ 419.5