XML 66 R54.htm IDEA: XBRL DOCUMENT v3.10.0.1
Significant Accounting Policies (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Marketable equity investments $ 1.5 $ 1.4  
Non-marketable equity investments 11.8 14.4  
Net foreign currency transaction gains (losses) $ 2.1 $ (7.8) $ 12.7
Percentage of revenue from largest client 3.00%    
Minimum [Member]      
Identifiable intangible assets, useful life 5 years    
Maximum [Member]      
Identifiable intangible assets, useful life 12 years    
Furniture [Member] | Minimum [Member]      
Property and Equipment, useful life 7 years    
Furniture [Member] | Maximum [Member]      
Property and Equipment, useful life 10 years    
Equipment [Member] | Minimum [Member]      
Property and Equipment, useful life 3 years    
Equipment [Member] | Maximum [Member]      
Property and Equipment, useful life 5 years