Segments - Reconciliation of Segment Gross Profit (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
	Sep. 27, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Gross profit		$ 24,287	$ 21,264	$ 20,645	$ 20,352	$ 22,038	$ 20,214	$ 19,249	$ 20,117	$ 86,548	$ 81,618	$ 57,745
Selling, general, and administrative expenses										34,667	32,718	27,555
Licensing and titling expenses										2,617	2,241	2,250
Amortization and non-rental depreciation										3,122	3,045	2,856
Transaction expenses		$ 200	3,300	$ 1,600	$ 2,500					7,641	440	202
Asset impairment	$ 700									657	0	610
Other operating expenses										1,826	10	784
Other (income) expense										1,690	287	366
Loss on extinguishment of debt			$ 4,000							4,005	0	0
Interest expense, net										63,361	56,698	53,710
Loss Before Income Taxes										$ (33,038)	$ (13,821)	$ (30,588)