Goodwill and Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Initial Carrying Value	$ 11,800		$ 11,800
Cumulative Foreign Currency Translation Adjustment	(9)	$ 199
Accumulated Amortization	(2,294)		(1,995)
Net Carrying Value	$ 9,497		10,004
Customer relationships - institutional
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)	14 years	14 years
Gross Initial Carrying Value	$ 3,200		3,200
Cumulative Foreign Currency Translation Adjustment	(3)	$ 57
Accumulated Amortization	(449)		(390)
Net Carrying Value	$ 2,748		2,867
Customer relationships - non-institutional
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)	10 years	10 years
Gross Initial Carrying Value	$ 4,400		4,400
Cumulative Foreign Currency Translation Adjustment	(3)	$ 74
Accumulated Amortization	(873)		(759)
Net Carrying Value	$ 3,524		3,715
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)	10 years	10 years
Gross Initial Carrying Value	$ 1,500		1,500
Cumulative Foreign Currency Translation Adjustment	(1)	$ 25
Accumulated Amortization	(297)		(259)
Net Carrying Value	$ 1,202		1,266
Developed technology
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)	8 years	8 years
Gross Initial Carrying Value	$ 2,700		2,700
Cumulative Foreign Currency Translation Adjustment	(2)	$ 43
Accumulated Amortization	(675)		(587)
Net Carrying Value	$ 2,023		$ 2,156