Accounting Policies - VIE Income Statement (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Accounting Policies [Abstract]
Revenue	$ 61,459	$ 26,883
Gross profit	9,720	1,949
Net income (loss) attributable to Aegion Corporation	$ 1,950	$ (3,098)