Other Income (Loss), Net (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Schedule Of Equity Method Investments [Line Items]
Realized gains on sales of marketable securities	$ 23	$ 1,446	$ 23	$ 1,446
Gains on sales/distributions of ownership interests		12		220
Other	(68)	12	(126)	(39)
Total other income (loss) for parent company	(45)	1,470	(103)	1,627
Total other income (loss) for consolidated core companies	106	(416)	(809)	(176)
Other income (loss), net	$ 61	$ 1,054	$ (912)	$ 1,451