Description of Business and Summary of Significant Accounting Policies (Assets and Liabilities Measured at Fair Value on a Recurring Basis using Significant Unobservable Inputs) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Contingent Liability for Accrued Earn-out Acquisition Consideration
Beginning balance	$ 10,095	$ 24,976
Gains included in earnings	(3,308)	(16,543)
Foreign currency translation adjustments	(554)	(260)
Business settlements	(2,881)
Business settlements		1,922
Ending balance	3,352	10,095
The amount of total (gains) losses for the period included in earnings or changes to net assets, attributable to changes in unrealized gains relating to assets or liabilities still held at period-end.	$ (3,308)	$ (16,543)