CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Revenues	$ 216,499	$ 209,240	$ 209,617
Operating expenses
Direct costs and expenses for advisors	132,359	124,701	124,132
Selling, general and administrative	78,863	67,841	65,434
Depreciation and amortization	7,869	7,083	7,373
Operating (loss) income	(2,592)	9,615	12,678
Interest income	27	14	18
Interest expense	(2,664)	(1,789)	(2,229)
Bargain purchase gain			146
Foreign currency transaction (loss) gain	(95)	303	(145)
(Loss) income before taxes	(5,324)	8,143	10,468
Income tax provision	1,054	3,189	4,164
Net (loss) income	(6,378)	4,954	6,304
Net income attributable to noncontrolling interest	127	113	126
Net (loss) income attributable to ISG	$ (6,505)	$ 4,841	$ 6,178
Weighted average shares outstanding:
Basic (in shares)	36,625	37,186	37,086
Diluted (in shares)	36,625	38,936	38,693
(Loss) earnings per share attributable to ISG:
Basic (in dollars per share)	$ (0.18)	$ 0.13	$ 0.17
Diluted (in dollars per share)	$ (0.18)	$ 0.13	0.16
Cash dividends declared			$ 0.14
Comprehensive (loss) income:
Net (loss) income	$ (6,378)	$ 4,954	$ 6,304
Foreign currency translation, net of tax (expense) benefit of $738, $1,102 and $1,128, respectively.	(1,262)	(1,956)	(2,134)
Comprehensive (loss) income	(7,640)	2,998	4,170
Comprehensive income attributable to noncontrolling interest	127	113	126
Comprehensive (loss) income attributable to ISG	$ (7,767)	$ 2,885	$ 4,044