Income Taxes - Reconciliation of Beginning and Ending Gross Amount of Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized tax benefits at beginning of year	$ 13,162	$ 14,141	$ 0
Additions based on tax positions related to the current year		7
Reductions for tax positions of prior years		(222)
Reductions due to settlements with taxing authorities	(12,327)
Reductions due to expiration of certain statute of limitations	(835)	(764)
Unrecognized tax benefits at end of year		$ 13,162	$ 0