Stock-Based Compensation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation, Nonemployee, Fair Value Increase (Decrease)	$ 80	$ 230
Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares	181	181
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	151	151
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation costs	$ 15,079	$ 15,079
Recognition over weighted average periods		2 years 7 months 8 days
Stock Options [Member] | Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		2 years 2 months