Acquisition - Narrative (Details) customer in Thousands, $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2020 USD ($) sale_representative customer	May 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	May 31, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Business Acquisition [Line Items]
Payments for purchase					$ 33,000		$ 2,300
Accrued acquisition liability			$ 0		0			$ 32,673
Interest expense			119	$ 142	710		329
Goodwill			35,253		35,253			35,176
Partsmaster
Business Acquisition [Line Items]
Number of customers | customer	16
Number of sales representatives | sale_representative	200
Payments for purchase	$ 2,300	$ 33,000				$ 35,300
Accrued acquisition liability								$ 32,700
Interest expense					300
Letter of credit	33,000
Goodwill	15,816
Revenue			13,600	5,400	44,600
Operating income since acquisition			$ 800	400	$ 400
Pro Forma revenue				101,200			298,500
Pro Forma net income				$ 2,000			$ 16,300
Partsmaster | Customer relationships
Business Acquisition [Line Items]
Intangibles	$ 4,961
Intangibles weighted average life	10 years
Partsmaster | Trade names
Business Acquisition [Line Items]
Intangibles	$ 2,775
Intangibles weighted average life	5 years