Other Income (Loss), Net (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule Of Equity Method Investments [Line Items]
Realized gains on sales of marketable securities		$ 106	$ 23	$ 1,552
Gains on sales/distributions of ownership interests		1,704		1,924
Other	6	(55)	(120)	(94)
Total other income (loss) for parent company	6	31,226	(97)	32,853
Total other income (loss) for consolidated core businesses	(74)	(4)	(81)	(4)
Other income (loss), net	(68)	31,222	(178)	32,849
CIML
Schedule Of Equity Method Investments [Line Items]
Gain on fair value upon consolidation of Channel Intelligence		26,563		26,563
Go Industry
Schedule Of Equity Method Investments [Line Items]
Gain on sale of GoIndustry		$ 2,908		$ 2,908