Summary of Significant Accounting Policies - Additional Information - Credit Risk Concentrations (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) Customer	Dec. 31, 2018 USD ($) Customer	Dec. 31, 2017 Customer
Accounting Policies [Line Items]
Uninsured cash balances | $	$ 23,327	$ 22,098
Number of customers who exceeded the company's total revenue threshold	0	0
Number of customers who exceeded the accounts receivable threshold	0	0
Net revenue [Member]
Accounting Policies [Line Items]
Number of customers who exceeded the company's total revenue threshold			0
Net revenue [Member] | Rush Trucker Center [Member]
Accounting Policies [Line Items]
Number of customers who exceeded the company's total revenue threshold			1
Purchases [Member]
Accounting Policies [Line Items]
Number of customers who exceeded the total purchasing threshold	0	0	0
Customer Concentration Risk [Member] | Rush Trucker Center [Member]
Accounting Policies [Line Items]
Minimum risk percentage threshold			12.00%