Employee Benefit Plan - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Compensation And Retirement Disclosure [Abstract]
Maximum tax deferred contributed by employees			$ 17,500
Portion of matching eligible compensation contributed to the plan by employer, First			100.00%
Percentage of eligible compensation contributed to the plan by employees, First			3.00%
Portion of matching eligible compensation contributed to the plan by employer, Second			50.00%
Percentage of eligible compensation contributed to the plan by employees, Second			2.00%
Company's contributions to the plan	$ 159,000	$ 126,000	$ 326,000	$ 261,000