Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jun. 20, 2017
Proceeds forgone upon exercise of stock options on a cashless basis		$ 508
Right of use asset	$ 18,161
Operating lease liabilities	22,739
Acquisition Of Etfs Business [Member]
Non-cash consideration transferred	$ 270,000
Common Stock [Member]
Business acquisition, number of shares to be issued	15,250,000
Convertible Preferred Stock [Member] | Thesys Group, Inc [Member] | Series Y Preferred Stock [Member]
Fair value of preferred stock		$ 3,080	$ 6,909