Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net foreign currency transaction gains (losses)	$ (4.8)	$ (11.2)	$ 2.1
Percentage of revenue from largest client	3.40%
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