XML 120 R93.htm IDEA: XBRL DOCUMENT v3.8.0.1
Risk Management and Derivatives (Foreign Exchange Contracts) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]      
Foreign currency transaction gain (loss) $ 0.2 $ 0.1 $ (0.1)