Commitments and Contingencies - Narrative (Details) $ in Thousands				1 Months Ended		12 Months Ended
	Sep. 27, 2019 USD ($)	May 16, 2017 USD ($) claimant	Mar. 06, 2015 class_action claimant	Apr. 30, 2017 USD ($) claimant	Jun. 30, 2015 USD ($)	Dec. 31, 2012 operator	Dec. 14, 2018 class_action	May 31, 2018 class_action
California Labor Commission
Loss Contingencies [Line Items]
Number of owner operators (in operators) | operator						150
Number of claims heard by court (in claimants) | claimant		5	170	4
Settlement amount awarded to other party | $	$ 812	$ 1,000			$ 1,000
Initial settlement amount awarded to other party | $				$ 1,000
Number of class actions related to remaining claimants (in class actions)			3
Last Mile Logistics Classifications Claims
Loss Contingencies [Line Items]
Number of class actions related to remaining claimants (in class actions)								4
Shareholder Litigation
Loss Contingencies [Line Items]
Number of class actions related to remaining claimants (in class actions)							2