Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2022	Apr. 22, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	1-8267
Entity Registrant Name	EMCOR Group, Inc.
Entity Central Index Key	0000105634
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	11-2125338
Entity Address, Address Line One	301 Merritt Seven
Entity Address, City or Town	Norwalk,
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06851-1092
City Area Code	(203)
Local Phone Number	849-7800
Title of 12(b) Security	Common Stock
Trading Symbol	EME
Security Exchange Name	NYSE
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		51,141,944