General Information - Adoption of New Accounting Standards (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to cash provided by (used for) operating activities	$ 300.0	$ 118.3
Increase to cash provided by (used for) investing activities	$ 360.3	105.7
Accounting Standards Update 2016-15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to cash provided by (used for) operating activities		424.8
Increase to cash provided by (used for) investing activities		$ 269.0