Stock Option Plan Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Options outstanding beginning	2,991
Shares, Granted	40
Shares, Exercised	(739)
Shares, Cancelled	(221)
Shares, Options outstanding ending	2,071
Shares, Vested or expected to Vest	2,058
Shares, Exercisable	1,547
Weighted Average Exercise Price, Options outstanding beginning	$ 12.91
Weighted Average Exercise Price, Granted	$ 13.86	$ 3.40
Weighted Average Exercise Price, Exercised	$ 10.51
Weighted Average Exercise Price, Canceled	$ 20.08
Weighted Average Exercise Price, Options outstanding ending	$ 13.03
Weighted Average Exercise Price, Vested or expected to vest	$ 13.08
Weighted Average Exercise Price, Exercisable	$ 15.98
Aggregate Intrinsic Value, Options outstanding ending	$ 5,095
Aggregate Intrinsic Value, Vested or expected to vest	4,990
Aggregate Intrinsic Value, Exercisable	$ 783
Weighted Average Remaining Term, Options outstanding ending, years	5 years 2 months 16 days
Weighted Average Remaining Term, vested or expected to vest, years	5 years 2 months 9 days
Weighted Average Remaining Term, Exercisable, years	4 years 1 month 28 days