Other Income (Loss), Net (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended				1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 SeaPass	Jul. 11, 2012 Channel Intelligence	Dec. 31, 2012 Channel Intelligence	Dec. 31, 2011 Channel Intelligence	Feb. 17, 2011 Metastorm	Dec. 31, 2012 Metastorm	Dec. 31, 2011 Metastorm	Dec. 31, 2012 Star Cite	Dec. 31, 2011 Star Cite	Dec. 31, 2011 Click Equations	Dec. 31, 2012 Creditex	Dec. 31, 2010 Creditex
Schedule of Equity Method Investments [Line Items]
Gain or Loss on sale												$ 25,501		$ 26,167		$ 24,900	$ 208	$ 25,988	$ 428	$ 14,054	$ (803)	$ 1,798	$ 5,179
Gain on sale/distributions of ownership interests									2,908	1,634	1,789											1,800	5,200
Realized gains on marketable securities									1,446		66,952
Dilution gain (loss) on equity method companies										496	(67)				(496)
Gain on other distributions										1,856
Other									(630)	(18)	654
Total other income (loss) for parent company									57,826	43,207	74,507
Total other income (loss) for consolidated core companies									53	(583)	(360)
Other income (loss), net	$ 24,859	$ 31,569	$ 1,054	$ 397	$ 16,440	$ (374)	$ 1,612	$ 24,946	$ 57,879	$ 42,624	$ 74,147		$ 26,200