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Fixed and Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Equipment and Leasehold Improvements, Net
Depreciation and amortization expenses	$ 1,076	$ 1,290	$ 2,275	$ 2,445
Prepaid Expenses and Other Assets
Equipment and Leasehold Improvements, Net
Costs capitalized	1,512		1,512
Communication, Technology and Information Services
Equipment and Leasehold Improvements, Net
Amortization expense of capitalized costs	$ 14		$ 14