Related Party Transactions - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Oct. 20, 2020	Oct. 19, 2020	Oct. 15, 2019
Related Party Transaction [Line Items]
Accrued interest - related party		$ 2,469,000		$ 2,469,000		$ 2,249,000
Common stock, shares issued		12,972,815		12,972,815		12,972,815
Warrants, exercise price						$ 0.01	$ 0.01	$ 2.50
Property and equipment, net		$ 29,075,000		$ 29,075,000		$ 28,240,000
CNG Tractors [Member]
Related Party Transaction [Line Items]
Common stock, shares issued									1,174,800
Warrant issued									1,174,800
Warrants, exercise price									$ 2.50
Property and equipment, net									$ 3,500,000
Accrued expenses									$ 3,500,000
Description of warrants				Company entered into an agreement with an existing stockholder to purchase used CNG tractors in exchange for 1,174,800 shares of the Company’s common stock and a warrant to purchase 1,174,800 shares of the Company’s common stock at an exercise price of $2.50 per share.
Officer [Member]
Related Party Transaction [Line Items]
Recognized operating lease expense		200,000	$ 300,000	$ 400,000	$ 600,000
Operating lease liabilities		$ 0		$ 0		$ 0
Sheehy Enterprises, Inc. [Member]
Related Party Transaction [Line Items]
Security deposit	$ 900,000
Sheehy Enterprises, Inc. [Member] | Collateral Security Pledge Agreement [Member]
Related Party Transaction [Line Items]
Security deposit	$ 900,000
Related party transaction, expiration date	Mar. 01, 2020