Income Taxes - Deferred Tax Valuation Allowance (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Balance, beginning of year	$ 1,500	$ 37,726	$ 39,049
Additions	0	0	0
Reductions, net		(36,226)	(1,323)
Balance, end of year	$ 1,500	$ 1,500	$ 37,726