Cover - USD ($)	12 Months Ended
	Dec. 31, 2022	Feb. 17, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	0-21220
Entity Registrant Name	ALAMO GROUP INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	74-1621248
Entity Address, Address Line One	1627 East Walnut
Entity Address, City or Town	Seguin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78155
City Area Code	830
Local Phone Number	379-1480
Title of 12(b) Security	Common Stock, par value$.10 per share
Trading Symbol	ALG
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,160,963,116
Entity Common Stock, Shares Outstanding		11,971,477
Documents Incorporated by Reference	Portions of the registrant’s proxy statement relating to the 2023 Annual Meeting of Stockholders have been incorporated by reference herein in response to Part III.
Entity Central Index Key	0000897077
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false