CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)
Stockholders' Equity Balance at Dec. 31, 2018	$ 377,693	$ 9	$ 377,473	$ 211
Stockholders' Equity Balance, shares at Dec. 31, 2018		87,512
Exercise of stock options	1,172		1,172
Exercise of stock options, shares		271
Restricted stock units vested, net of tax settlement, shares		91
Stock-based compensation expense	4,639		4,639
Vested incentive units converted to common stock	37		37
Vested incentive units converted to common stock, shares		724
Net loss	(8,390)			(8,390)
Stockholders' Equity Balance at Mar. 31, 2019	375,151	$ 9	383,321	(8,179)
Stockholders' Equity Balance, shares at Mar. 31, 2019		88,598
Stockholders' Equity Balance at Dec. 31, 2019	434,127	$ 9	442,407	(8,289)
Stockholders' Equity Balance, shares at Dec. 31, 2019		89,676
Exercise of stock options	1,317		1,317
Exercise of stock options, shares		228
Restricted stock units vested, net of tax settlement	(155)		(155)
Restricted stock units vested, net of tax settlement, shares		265
Stock-based compensation expense	6,191		6,191
Net loss	(8,417)			(8,417)
Stockholders' Equity Balance at Mar. 31, 2020	432,704	$ 9	$ 449,760	(17,065)
Stockholders' Equity Balance, shares at Mar. 31, 2020		90,169
Cumulative effect adjustment from the adoption of ASC 326, net of tax | ASC 326	$ (359)			$ (359)