Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ (73,782)	$ 11,787	$ (53,851)	$ 11,031
Other comprehensive income (loss):
Currency translation adjustments		(250)	3,885	16,188	2,928
Deferred gain (loss) on hedging activity, net of tax	[1]	89	895	265	(3,163)
Pension activity, net of tax	[2]	(9)	90	(25)	(83)
Total comprehensive income (loss)		(73,952)	16,657	(37,423)	10,713
Comprehensive (income) loss attributable to non-controlling interests		480	365	(2,500)	593
Comprehensive income (loss) attributable to Aegion Corporation		$ (73,472)	$ 17,022	$ (39,923)	$ 11,306

[1] Amounts presented net of tax of $59 and $617 for the quarters ended September 30, 2017 and 2016, respectively, and $176 and $(2,100) for the nine months ended September 30, 2017 and 2016, respectively.

[2] Amounts presented net of tax of $(2) and $23 for the quarters ended September 30, 2017 and 2016, respectively, and $(6) and $(21) for the nine months ended September 30, 2017 and 2016, respectively.