Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 3,087	$ (66,582)	$ 29,125
Other comprehensive income (loss):
Currency translation adjustments		(14,651)	20,839	(6,343)
Deferred gain (loss) on hedging activity, net of tax	[1]	(1,621)	1,402	746
Pension activity, net of tax	[2]	(654)	93	(8)
Total comprehensive income (loss)		(13,839)	(44,248)	23,520
Comprehensive (income) loss attributable to non-controlling interests		(1)	(3,040)	294
Comprehensive income (loss) attributable to Aegion Corporation		$ (13,840)	$ (47,288)	$ 23,814

[1] Amounts presented net of tax of $(48), $930 and $496 for the years ended December 31, 2018, 2017 and 2016, respectively.

[2] Amounts presented net of tax of $(134), $22 and $(2) for the years ended December 31, 2018, 2017 and 2016, respectively.