XML 82 R68.htm IDEA: XBRL DOCUMENT v3.8.0.1
Fair Value of Financial Instruments - Time and Call Deposits (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Investments in time and call deposits    
Cash equivalents $ 0.0  
Restricted cash 4.0 $ 3.4
Short-term investments $ 114.2 $ 157.9
Minimum    
Investments in time and call deposits    
Maturity of time deposits 1 month  
Period of ability to redeem invested amounts on call deposits 31 days  
Maximum    
Investments in time and call deposits    
Maturity of time deposits 12 months  
Period of ability to redeem invested amounts on call deposits 95 days