Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues	$ 341,872	$ 308,524	$ 1,021,520	$ 900,118
Cost of revenues	268,430	242,206	800,898	718,196
Gross profit	73,442	66,318	220,622	181,922
Operating expenses	54,610	45,277	165,465	146,808
Goodwill impairment	45,390	0	45,390	0
Definite-lived intangible asset impairment	41,032	0	41,032	0
Acquisition and divestiture expenses	1,980	324	2,513	2,059
Restructuring and related charges	5,439	212	5,439	8,544
Operating income (loss)	(75,009)	20,505	(39,217)	24,511
Other income (expense):
Interest expense	(3,962)	(3,825)	(12,014)	(11,081)
Interest income	33	37	117	197
Other	(798)	288	(1,593)	(1,183)
Total other expense	(4,727)	(3,500)	(13,490)	(12,067)
Income (loss) before taxes on income	(79,736)	17,005	(52,707)	12,444
Taxes (benefit) on income (loss)	(5,954)	5,218	1,144	1,413
Net income (loss)	(73,782)	11,787	(53,851)	11,031
Non-controlling interests (income) loss	546	280	(2,414)	666
Net income (loss) attributable to Aegion Corporation	$ (73,236)	$ 12,067	$ (56,265)	$ 11,697
Earnings (loss) per share attributable to Aegion Corporation:
Net income (loss) per share, basic (in dollars per share)	$ (2.23)	$ 0.35	$ (1.69)	$ 0.33
Net income (loss) per share, diluted (in dollars per share)	$ (2.23)	$ 0.34	$ (1.69)	$ 0.33