Accrued Acquisition Liability (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2020	May 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	May 31, 2021	Sep. 30, 2020	Dec. 31, 2020
Business Acquisition [Line Items]
Payments for purchase					$ 33,000		$ 2,300
Implied interest rate	1.80%
Accrued acquisition liability			$ 0		0			$ 32,673
Interest expense			$ 119	$ 142	710		$ 329
Partsmaster
Business Acquisition [Line Items]
Payments for purchase	$ 2,300	$ 33,000				$ 35,300
Accrued acquisition liability								$ 32,700
Interest expense					$ 300