Recent Accounting Changes and Pronouncements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Other income (expense) – net	$ 5.7	$ 3.1	$ 8.6	$ 4.0
Engineering, selling, and administrative expense	(62.1)	$ (59.0)	(184.6)	(178.8)
Operating cash flows			441.1	294.1
Investing cash flows			412.7	$ 249.9
Accounting Standards Update 2017-07
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Other income (expense) – net	1.9		5.8
Engineering, selling, and administrative expense	$ 1.9		5.8
Accounting Standards Update 2016-15
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Operating cash flows			259.9
Investing cash flows			$ 259.9