Assets Acquisition - Additional Information (Details) - EH Trucking		6 Months Ended
	May 06, 2019 USD ($) trailer truck $ / shares shares	Jun. 30, 2019 USD ($)
Schedule of Asset Acquisition [Line Items]
Consideration transferred	$ 6,434,000
Payments for asset acquisitions, cash	$ 5,611,000
Number of shares (in shares) | shares	11,145
Value assigned to shares	$ 400,000
Contingent consideration, liability	$ 400,000
Number of tractor trailer trucks | truck	39
Number of trailers | trailer	53
Transaction sosts	$ 100,000
Share price | $ / shares	$ 35.15
Maximum quarterly payment	$ 146,875
Range of outcomes, value, low	0
Range of outcomes, value, high	$ 587,500
Customer Relationships
Schedule of Asset Acquisition [Line Items]
Useful life	7 years
Amortization expense		$ 100,000