Equity-based Compensation Plans - Summary of Equity-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Equity-based compensation expense:
Equity based compensation expense	$ 5,109	$ 1,597
Total income tax benefit recognized related to equity-based compensation	619	125
Costs applicable to revenue
Equity-based compensation expense:
Equity based compensation expense	386	90
Selling, general, and administrative
Equity-based compensation expense:
Equity based compensation expense	$ 4,723	$ 1,507