Subsequent Events - Agreement With Triumph Business Capital - Additional Information (Details)		1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 09, 2021 USD ($) Installment	Oct. 31, 2018 USD ($)	Mar. 31, 2021 USD ($) Installment	Dec. 31, 2018 USD ($)
Subsequent Event [Line Items]
Repayment of factor advances		$ 100,000		$ 105,000
Triumph Business Capital [Member] | Letter of Intent and Memo of Understanding [Member] | Forecast [Member]
Subsequent Event [Line Items]
Proceeds from transportation settlements	$ 17,500,000		$ 17,500,000
Repayment of factor advances	11,000,000.0		11,000,000.0
Amount retained to reduce outstanding principal amount of factoring advances	$ 6,900,000		$ 6,900,000
Number of installments for repayment | Installment	48		48
Frequency of payments	monthly		monthly
Date of first required payment	Jan. 01, 2022		Jan. 01, 2022
Funds held in reserve against advances	$ 800,000		$ 800,000