Cover Page - shares	6 Months Ended
	Jun. 30, 2023	Aug. 04, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-38186
Entity Registrant Name	CUSTOM TRUCK ONE SOURCE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-2531628
Entity Address, Address Line One	7701 Independence Ave
Entity Address, City or Town	Kansas City
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	64125
City Area Code	816
Local Phone Number	241-4888
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		246,262,581
Entity Central Index Key	0001709682
Document Fiscal Year Focus	2023
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Stock, $0.0001 par value per share
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	CTOS
Security Exchange Name	NYSE
Redeemable warrants, exercisable for Common Stock, $0.0001 par value per share
Document Information [Line Items]
Title of 12(b) Security	Redeemable warrants, exercisable for Common Stock, $0.0001 par value per share
Trading Symbol	CTOS.WS
Security Exchange Name	NYSE