Income Taxes - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Expected income tax provision at the federal statutory rate			34.00%
Effective tax rate (ETR)	2.10%	(0.60%)	(1.60%)	(1.50%)