Income Tax - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Schedule Of Income Taxes [Line Items]
Effective income tax rate	(1.20%)	(1.90%)	(1.60%)	(1.00%)
U.S federal statutory rate	35.00%	35.00%	35.00%	35.00%
Interest or penalties related to uncertain tax positions	$ 0		$ 0
Liabilities for interest and potential penalties	0		0
Unrecognized tax benefits	0		0
Scenario, Forecast [Member]
Schedule Of Income Taxes [Line Items]
Increase (decrease) in unrecognized tax benefits			$ 0