The Company - Additional Information (Details) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
	Oct. 02, 2017 USD ($) Vote $ / shares shares	Mar. 31, 2018 segment
Entity Wide Revenue Major Customer [Line Items]
Conversion date		Feb. 01, 2008
Number of reportable segments operates | segment		2
Class A Common Stock
Entity Wide Revenue Major Customer [Line Items]
Number of votes per share | Vote	1
Class B Common Stock
Entity Wide Revenue Major Customer [Line Items]
Number of votes per share | Vote	10
Initial Public Offering | Class B Common Stock Warrants
Entity Wide Revenue Major Customer [Line Items]
Warrants conversion ratio	100.00%
Initial Public Offering | Class A Common Stock
Entity Wide Revenue Major Customer [Line Items]
Initial public offering completed date	Oct. 02, 2017
Number of shares sold	10.4
Share sold price per share | $ / shares	$ 14.00
Net proceeds from shares sold | $	$ 134.8
Underwriting discounts and commissions | $	$ 10.1
Initial Public Offering | Class B Common Stock
Entity Wide Revenue Major Customer [Line Items]
Convertible preferred stock, Shares converted	80.8
Stock conversion ratio	100.00%
Over-Allotment Option | Class A Common Stock
Entity Wide Revenue Major Customer [Line Items]
Number of shares sold	1.4