Consolidated Statements Of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenues	$ 9,903,580	$ 8,797,061	$ 9,174,611
Cost of sales	8,401,843	7,401,679	7,818,743
Gross profit	1,501,737	1,395,382	1,355,868
Selling, general and administrative expenses	970,937	903,584	893,453
Restructuring Charges	0	2,214	1,523
Asset Impairment Charges	0	232,750	0
Operating income	530,800	256,834	460,892
Net periodic pension (cost) income	3,625	2,980	1,553
Interest expense	(6,071)	(9,009)	(13,821)
Interest income	949	1,521	2,265
Income before income taxes	529,303	252,326	450,889
Income tax provision	145,602	119,383	125,749
Net income including noncontrolling interests	383,701	132,943	325,140
Net income attributable to noncontrolling interests	169	0	0
Net income attributable to EMCOR Group, Inc. (in US dollars)	$ 383,532	$ 132,943	$ 325,140
Basic earnings per common share (in US dollars per share)	$ 7.09	$ 2.41	$ 5.78
Diluted earnings per common share (in US dollars per share)	7.06	2.40	5.75
Dividends declared per common share (in US dollars per share)	$ 0.52	$ 0.32	$ 0.32