Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts receivable, allowance for credit losses	$ 120	$ 195
Preferred stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)	250,000,000	250,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A Common Stock
Common Stock, par value (in dollars per share)	$ 0.00001
Common Stock, shares authorized (in shares)	1,000,000,000
Common stock, shares issued (in shares)	90,985,582
Common stock, shares outstanding (in shares)	90,985,582
Class B Common Stock
Common Stock, par value (in dollars per share)	$ 0.00001
Common Stock, shares authorized (in shares)	450,000,000
Common stock, shares issued (in shares)	96,933,192
Common stock, shares outstanding (in shares)	96,933,192
Class C Common Stock
Common Stock, par value (in dollars per share)	$ 0.00001
Common Stock, shares authorized (in shares)	350,000,000
Common stock, shares issued (in shares)	5,109,991
Common stock, shares outstanding (in shares)	5,109,991
Class D Common Stock
Common Stock, par value (in dollars per share)	$ 0.00001
Common Stock, shares authorized (in shares)	300,000,000
Common stock, shares issued (in shares)	34,403,255
Common stock, shares outstanding (in shares)	34,403,255