Consolidated Statements Of Operations And Comprehensive Income (Loss) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Operations And Comprehensive Income (Loss) [Abstract]
Revenues	$ 36,630	$ 33,954
Operating expenses
Cost of revenue	23,625	20,990
Selling, general and administrative	13,591	11,587
Research and development	3,314	3,129
Amortization of intangible assets	424	337
Impairment related and other	127	37
Total operating expenses	41,081	36,080
Operating income (loss)	(4,451)	(2,126)
Other income (loss), net	397	24,946
Interest income	137	84
Interest expense	(108)	(146)
Income (loss) before income taxes, equity loss and noncontrolling interest	(4,025)	22,758
Income tax (expense) benefit	(540)	(2,940)
Equity loss	(2,303)	(3,576)
Net income (loss)	(6,868)	16,242
Less: Net income attributable to the noncontrolling interest	152	352
Net income (loss) attributable to ICG Group, Inc.	(7,020)	15,890
Basic income (loss) per share attributable to ICG Group, Inc.	$ (0.19)	$ 0.43
Shares used in computation of basic income (loss) per share	36,156	36,944
Diluted income (loss) per share attributable to ICG Group, Inc.	$ (0.19)	$ 0.42
Shares used in computation of diluted income (loss) per share	36,156	37,991
Net income (loss)	(6,868)	16,242
Other comprehensive income (loss)
Other accumulated other comprehensive income (loss)	(14)	(20)
Comprehensive income (loss)	(6,882)	16,222
Less: Comprehensive income attributable to the noncontrolling interest	138	332
Comprehensive income (loss) attributable to ICG Group, Inc.	$ (7,020)	$ 15,890