Intrinsic Value of Options Exercised and Fair Value of Options Vested (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2014		Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award Options Additional Disclosures [Abstract]
Intrinsic value of common stock options exercised	$ 132	[1]	$ 137	[1]
Fair value of common stock options vested	$ 1,111	[2]	$ 756	[2]

[1] The intrinsic value of common stock options exercised is the difference between the fair market value of the Company’s common stock on the exercise date and the exercise price.

[2] The fair value of common stock options vested is based on the grant date fair value.