Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]
Effective income tax rate	(153.70%)	50.60%	(72.80%)	127.20%
Deferred tax assets valuation allowance	$ 2.2		$ 2.2