Investments In Mutual Funds (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Investments [Line Items]
Cost	$ 144,353	$ 59,598	$ 24,817
Unrealized gain, net	5,475	948	210
Fair value	149,828	60,546	25,027
Gross realized gains	3,600	3,012	2,539
Proceeds on sales of mutual funds	200,836	238,604	219,032
Purchases of mutual funds	$ 294,010	$ 270,685	$ 213,829