Acquisition - Narrative (Details) customer in Thousands, $ in Thousands		1 Months Ended	3 Months Ended
	Aug. 31, 2020 USD ($) customer sale_representative	May 31, 2021 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Accrued acquisition liability			$ 32,871		$ 32,673
Interest expense			323	$ 115
Goodwill			35,426	19,555	35,176	$ 20,923
Partsmaster
Business Acquisition [Line Items]
Number of customers | customer	16
Number of sales representatives | sale_representative	200
Purchase price	$ 35,300
Payments for purchase	2,300
Accrued acquisition liability			32,900		$ 32,700
Interest expense			200
Goodwill	15,816
Fair value of accounts receivable not expected to be collected	400
Revenue			15,700
Operating income since acquisition			$ 700
Pro Forma revenue				106,200
Pro Forma net income				$ 12,900
Partsmaster | Forecast
Business Acquisition [Line Items]
Payments for purchase		$ 33,000
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