Number and Cost of Employee Stock Plan Repurchases (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Uncategorized [Abstract]
Employee stock plan repurchased (in shares)	1,157	1,661	1,020
Employee stock plan repurchased	$ 44,169	$ 50,045	$ 29,017