Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1,	$ 51,433	$ 48,055
Increase based upon tax positions of current year	535	927
Increase based upon tax positions of a prior year	139	701
Increase due to acquisitions	27,086	3,316
Decrease based upon settlements with taxing authorities	(28,346)	0
Decrease based upon a lapse in the statute of limitations	(449)	(1,566)
Balance at December 31,	$ 50,398	$ 51,433