Introduction (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Aug. 05, 2019	May 06, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Subsidiary, Sale of Stock [Line Items]
Payments of deferred offering costs			$ 0	$ 2,415	$ 0
IPO
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)		11,068,750
Sale of stock, price per share (in dollars per share)		$ 25.00
Proceeds from IPO, net		$ 252,400
Underwriting discounts and commissions		19,400
Sale of stock, issuance costs		$ 4,900
Number of common stock shares converted		41,562,111
Number of shares issued for each share of convertible preferred stock converted (in shares)		1
Payments of deferred offering costs			2,500	$ 2,400
Deferred offering costs		$ 4,900	4,900
Secondary Offering
Subsidiary, Sale of Stock [Line Items]
Sale of stock, price per share (in dollars per share)	$ 160.00
Proceeds from IPO, net	$ 37,400
Underwriting discounts and commissions	1,500
Sale of stock, issuance costs	$ 1,100
Selling stockholders sold (in shares)	3,487,500
Payments of deferred offering costs			2,200
Deferred offering costs			$ 1,100
Over-allotment option
Subsidiary, Sale of Stock [Line Items]
Selling stockholders sold (in shares)	250,000
Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of common stock shares converted			41,562,111
Common Stock | IPO
Subsidiary, Sale of Stock [Line Items]
Number of common stock shares converted			11,068,750
Number of shares able to purchase		160,767
Common Stock | Secondary Offering
Subsidiary, Sale of Stock [Line Items]
Number of common stock shares converted			250,000