v3.10.0.1
Derivative Instruments (Net Cash Received (Paid) Related to Derivatives) (Schedule) (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]    
Operating activities $ 246.1 $ 89.5
Investing activities 0.0 (0.5)
Financing activities 10.2 (139.0)
Total $ 256.3 $ (50.0)