Condensed Consolidated Statements Of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenues	$ 2,158,728	$ 1,900,388
Cost of sales	1,849,974	1,631,269
Gross profit	308,754	269,119
Selling, general and administrative expenses	206,169	191,025
Restructuring expenses	275	90
Operating income	102,310	78,004
Net periodic pension (cost) income	406	737
Interest expense, net	(2,823)	(2,452)
Income from continuing operations before income taxes	99,893	76,289
Income tax provision	27,483	20,633
Income from continuing operations	72,410	55,656
Loss from discontinued operation, net of income taxes	0	(282)
Net income including noncontrolling interests	72,410	55,374
Less: Net income attributable to noncontrolling interests	0	0
Net income attributable to EMCOR Group, Inc. (in US dollars)	$ 72,410	$ 55,374
Basic earnings (loss) per common share:
From continuing operations attributable to EMCOR Group, Inc. common stockholders (in US dollars per share)	$ 1.29	$ 0.95
From discontinued operation (in US dollars per share)	0	0.00
Net income attributable to EMCOR Group, Inc. common stockholders (in US dollars per share)	1.29	0.95
Diluted earnings (loss) per common share:
From continuing operations attributable to EMCOR Group, Inc. common stockholders (in US dollars per share)	1.28	0.94
From discontinued operation (in US dollars per share)	0	0.00
Net income attributable to EMCOR Group, Inc. common stockholders (in US dollars per share)	1.28	0.94
Dividends declared per common share (in US dollars per share)	$ 0.08	$ 0.08