XML 60 R50.htm IDEA: XBRL DOCUMENT v3.7.0.1
Fair Value of Financial Instruments - Time and Call Deposits (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Investments in time and call deposits    
Period of ability to redeem invested amounts on call deposits 95 days  
Cash equivalents $ 0.0  
Restricted cash 3.7 $ 3.5
Short-term investments $ 222.6 $ 157.9
Minimum    
Investments in time and call deposits    
Maturity of time deposits 1 month  
Maximum    
Investments in time and call deposits    
Maturity of time deposits 12 months