Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator
Net income attributable to EMCOR Group, Inc. common stockholders (in US dollars)	$ 73,386	$ 84,774
Denominator
Weighted average shares outstanding used to compute basic earnings per common share (in shares)	52,713,005	54,896,548
Effect of dilutive securities-Share-based awards (in shares)	203,554	238,756
Shares used to compute diluted earnings per common share (in shares)	52,916,559	55,135,304
Basic earnings per common share (in US dollars per share)	$ 1.39	$ 1.54
Diluted earnings per common share (in US dollars per share)	$ 1.39	$ 1.54
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive share-based awards excluded from calculation of diluted earnings per share (in shares)	62,481	0