Stock-Based Compensation - Employee Stock Purchase Plan ("ESPP") - Additional Information (Detail) (Employee Stock Purchase Plan ("ESPP") [Member], USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Mar. 31, 2014
Employee Stock Purchase Plan ("ESPP") [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of fair market value to determine purchase price			85.00%
Offering period			6 months
Proceeds of from issuance of shares under ESPP	$ 0.3	$ 0.3
Options issued	49,063	61,230
Rate of discount on fair market value of common stock under ESPP			15.00%
Period of expected life, options granted			5 years