Subsequent Events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	6 Months Ended
	Aug. 01, 2017	Jun. 29, 2017	Sep. 30, 2017	Jul. 31, 2017	Jul. 31, 2016
Subsequent Event [Line Items]
Description of underwriting agreement		On June 29, 2017, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with Morgan Stanley & Co. LLC and Merrill Lynch, Pierce, Fenner & Smith Incorporated (the “Underwriters”), relating to the Company’s IPO.
Period granted for underwriting option		30 days
Proceeds from initial public offering, net of underwriting discounts and commissions				$ 55,804	$ 0
Subsequent Event | Employee Stock Option | 2017 Equity Incentive Plan
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period			58,966
Share-based compensation arrangement by share-based payment award options grant date fair value			100,000
Subsequent Event | PSUs | 2017 Equity Incentive Plan
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options ,grants in period			3,662,534
Share-based compensation arrangement by share-based payment award equity instruments other than options grant date fair value			16,300,000
Over-allotment Option | Common Stock
Subsequent Event [Line Items]
Number of additional shares issued		1,285,800
Over-allotment Option | Common Stock | Subsequent Event
Subsequent Event [Line Items]
Number of shares issued	1,000,000
Shares price	$ 7.00
Proceeds from initial public offering, net of underwriting discounts and commissions	$ 6,500
Underwriting discounts and commissions	$ 500