Other Income (Loss), Net (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Equity Method Investments [Line Items]
Gain on fair value of prior equity interest										$ 51,668
Gain (loss) on sales/distributions of ownership interests									(4,032)	5,260	40,873
Realized gains on sales of marketable securities									23	1,552
Gain on other distributions											1,856
Dilution gain on equity method businesses											496
Other									(93)	(656)	(18)
Total other income (loss) for parent company									(4,102)	57,824	43,207
Total other income (loss) for consolidated businesses									(108)	(4)	(4)
Other income (loss), net	$ (4,032)	$ (68)	$ (46)	$ (64)	$ 24,971	$ 31,222	$ 1,470	$ 157	$ (4,210)	$ 57,820	$ 43,203