Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements of Operations and Comprehensive Income (Loss) [Abstract]
Revenue	$ 45,078	$ 35,328	$ 81,708	$ 69,282
Operating expenses
Cost of revenue	27,018	21,775	50,643	42,765
Selling, general and administrative	15,199	12,115	28,790	23,702
Research and development	4,038	3,325	7,352	6,454
Amortization of intangible assets	1,436	338	1,860	675
Impairment related and other	160	82	287	119
Total operating expenses	47,851	37,635	88,932	73,715
Operating income (loss)	(2,773)	(2,307)	(7,224)	(4,433)
Other income (loss), net	1,054	1,612	1,451	26,558
Interest income	93	124	230	208
Interest expense	(88)	(186)	(196)	(332)
Income (loss) before income taxes and equity loss	(1,714)	(757)	(5,739)	22,001
Income tax (expense) benefit	(392)	963	(932)	(1,977)
Equity loss	(3,236)	(3,185)	(5,539)	(6,761)
Less: Net income attributable to the non controlling interest	652	254	804	606
Net income (loss) attributable to ICG Group, Inc.	(5,994)	(3,233)	(13,014)	12,657
Basic income (loss) per share attributable to ICG Group, Inc.	$ (0.17)	$ (0.09)	$ (0.36)	$ 0.34
Shares used in computation of basic income (loss) per share	35,917	36,961	36,037	36,953
Diluted income (loss) per share attributable to ICG Group, Inc.	$ (0.17)	$ (0.09)	$ (0.36)	$ 0.33
Shares used in computation of diluted income (loss) per share	35,917	36,961	36,037	37,976
Net income (loss)	(5,342)	(2,979)	(12,210)	13,263
Other comprehensive income (loss)
Unrealized holding gains (losses) in marketable securities	1,565		1,565
Reclassification adjustments/realized net gains on marketable securities	(1,446)		(1,446)
Other accumulated other comprehensive income (loss)	23	5	9	(15)
Comprehensive income (loss)	(5,200)	(2,974)	(12,082)	13,248
Less: Comprehensive income attributable to the non controlling interest	675	259	813	591
Comprehensive income (loss) attributable to ICG Group, Inc.	$ (5,875)	$ (3,233)	$ (12,895)	$ 12,657