Business Combinations Hudson Net Assets Acquired (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	Sep. 20, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 468.8				$ 218.0	$ 218.4
Restricted Cash and Cash Equivalents	8.8
Hudson [Member]
Business Acquisition [Line Items]
Goodwill	238.3		$ 227.4
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill	10.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	211.0		202.0	$ 211.0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles	9.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	34.6		34.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	29.4		30.6
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment	1.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	26.5		24.9
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory	1.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other	8.1	[1]	9.3
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other current assets	1.2
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Unbilled Contract Revenue	4.9		4.6
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Unbilled contract revenue	0.3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	2.9		2.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets	0.9		0.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent	87.6		68.6
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred tax liabilities	19.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	21.2		21.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Customer Advances and Billings In Excess of Contract Revenue	17.4		16.9
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Customer advances and billings in excess of contract revenue	0.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Accrued Salaries Wages and Benefits	4.4		4.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other	3.8		4.0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other current liabilities	0.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	1.9		1.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Current portion of warranty reserve	0.8		0.8
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	419.5		$ 419.4
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	$ 0.1
Restricted Cash and Cash Equivalents				$ 2.3

[1] (1) Pursuant to the provisions of the Merger Agreement, Hudson deposited $2.3 into a Rabbi Trust which represents amounts payable to eligible parties under Long-Term Incentive Agreements. This balance is treated as restricted cash and restricted cash equivalents in the consolidated balance sheets and is classified as other current assets.