Description of Business and Summary of Significant Accounting Policies - Additional Information (Details)					1 Months Ended		3 Months Ended				12 Months Ended
	Mar. 09, 2021 USD ($)	Mar. 09, 2021 USD ($) Installment	Feb. 19, 2021 USD ($)	Jan. 19, 2021 USD ($)	Feb. 28, 2021 USD ($)	Jan. 31, 2021 USD ($)	Jun. 30, 2021 USD ($) $ / shares shares	Mar. 31, 2021 USD ($) Installment Station Acquisition $ / shares shares	Dec. 31, 2020 USD ($) $ / shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) $ / shares	Mar. 31, 2022 USD ($) $ / shares shares	Apr. 30, 2021 USD ($) $ / shares shares	Mar. 03, 2021 USD ($) Facility	Oct. 20, 2020 $ / shares shares	Oct. 19, 2020 $ / shares shares	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 shares
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of facilities in operation | Facility														10
Number of acquisitions completed | Acquisition								7
Cash								$ 16,287,000	$ 26,644,000		$ 26,644,000			$ 16,300,000
Working capital deficit														$ 64,100,000
Stockholders' deficit								(33,888,000)	$ (67,322,000)	$ (34,152,000)	$ (67,322,000)								$ (12,673,000)
Cash provided by operating activities								17,693,000		(15,881,000)
Debt and lease obligations																	$ 125,000,000.0
Net income								(31,223,000)		13,702,000
(Gain) loss on extinguishment of debt								534,000		(10,086,000)
Warrants, exercise price | $ / shares									$ 0.01		$ 0.01				$ 0.01	$ 2.50
Accumulated deficit								70,396,000	$ 101,619,000		$ 101,619,000
Total revenue								88,846,000		55,726,000
Finance lease right-of-use assets, net								25,844,000	27,913,000		27,913,000
Operating lease right-of-use assets, net								8,212,000	10,473,000		10,473,000
Warrants to purchase common stock | shares															5,072,000	7,925,000
Trucking [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Total revenue								$ 53,952,000		55,406,000
ASU 2019-12 [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]								true
Change in accounting principle, accounting standards update, adoption date								Jan. 01, 2021
Change in accounting principle, accounting standards update, immaterial effect true false]								true
Letter of Intent and Memo of Understanding [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Proceeds from transportation settlements	$ 1,600,000				$ 17,500,000	$ 7,100,000
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 utilized						$ 3,000,000.0
Funds held in reserve against advances	800,000	$ 800,000						$ 800,000
Letter of Intent and Memo of Understanding [Member] | Triumph Business Capital [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Transportation Settlements Fund Held in Reserve	$ 600,000	$ 600,000
USPS [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Nonrecurring cash receipts from settlement agreements								28,500,000
Pre-tax nonrecurring revenue from settlement agreements								34,800,000
Compensation received for work performed								28,500,000
Additional settlement payment including rate adjustments under settlement agreement									3,800,000
Other operating revenue								34,800,000
Payments for transportation settlements			$ 17,500,000	$ 7,100,000
Common Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Stockholders' deficit								$ 2,000	2,000	$ 1,000	2,000								$ 1,000
Warrants to purchase common stock | shares																				4,375,000
2.50 Warrant [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Warrants to purchase shares of common stock | shares								950,000
Warrants, exercise price | $ / shares								$ 2.50
0.01 Warrant [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Warrants to purchase shares of common stock | shares								250,000
Warrants, exercise price | $ / shares								$ 0.01
Paycheck Protection Program Loan CARES Act [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Principal amount																		$ 10,000,000.0
Note Purchase Agreements and Releases [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Principal amount								$ 3,600,000
Notes payable in cash								$ 500,000
Warrants to purchase shares of common stock | shares								1,356,343
Warrants, exercise price | $ / shares								$ 0.01
Note Purchase Agreements and Releases [Member] | 2.50 Warrant [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Warrants to purchase shares of common stock | shares								1,200,000
Warrants, exercise price | $ / shares								$ 2.50
Subsequent Event [Member] | Bridge Loan and Executive Loans [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Agreegate amount												$ 9,800,000
Subsequent Event [Member] | Amendments to Secured Convertible Promissory Notes [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Warrants, exercise price | $ / shares												$ 0.01
Agreegate amount												$ 9,500,000
Warrants to purchase common stock | shares												7,553,750
Subsequent Event [Member] | Note Purchase Agreements and Releases [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
(Gain) loss on extinguishment of debt							$ 200
Principal amount							300,000						$ 300,000
Notes payable in cash							$ 100,000						$ 100,000
Warrants to purchase shares of common stock | shares							125,110						125,110
Warrants, exercise price | $ / shares							$ 0.01						$ 0.01
Antara Financing Agreement [Member] | Main Street Loan [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Principal amount due								$ 16,700,000	33,600,000		33,600,000
Loan Agreement [Member] | Main Street Loan [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Principal amount									$ 17,000,000.0		17,000,000.0
Settlement Agreement [Member] | USPS [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Deferred gain recognized											$ 6,300,000
CNG [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of fueling stations | Station								1
Number of compressed natural gas stations | Station								3