Accounts Receivable, Net and Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Accounts Receivable, Net and Contract Assets and Liabilities [Line Items]
Revenue recognition, BIEC, revenue recognized	$ 84.8
Provisions for doubtful accounts	0.8	$ 0.5
Interest Expense [Member] | Accounts Receivable Financing Arrangements [Member]
Schedule of Accounts Receivable, Net and Contract Assets and Liabilities [Line Items]
Non-recourse financing arrangements, discount charge	$ 1.9	$ 0.9
Minimum [Member]
Schedule of Accounts Receivable, Net and Contract Assets and Liabilities [Line Items]
Retainage, percent of contract billings	5.00%
Maximum [Member]
Schedule of Accounts Receivable, Net and Contract Assets and Liabilities [Line Items]
Retainage, percent of contract billings	10.00%