Share-Based Compensation - Stock Option Activities (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Number of Shares
Number of Shares, Options outstanding, beginning balance	5,167
Number of Shares, Granted	1,842
Number of shares, Exercised	(216)
Number of Shares, Forfeited	(86)
Number of Shares, Expired	(2,215)
Number of Shares, Options outstanding, ending balance	4,492
Number of Shares, Vested and expected to vest at end of period	4,365
Number of Shares, Options exercisable at end of period	2,598
Weighted-Average Exercise Price Per Share
Weighted Average Exercise Price, Options outstanding, beginning balance	$ 11.08
Weighted Average Exercise Price, Granted	$ 6.53
Weighted Average Exercise Price, Exercised	$ 7.66
Weighted Average Exercise Price, Forfeited	$ 6.77
Weighted Average Exercise Price, Expired	$ 11.15
Weighted Average Exercise Price, Options outstanding, ending balance	$ 9.42
Weighted Average Exercise Price, Vested and expected to vest at end of period	$ 9.51
Weighted Average Exercise Price, Options exercisable at end of period	$ 11.48
Weighted-Average Remaining Contractual Term
Weighted Average Remaining Life, Options outstanding at end of period	5 years 7 months 28 days
Weighted Average Remaining Life, Vested and expected to vest at end of period	5 years 6 months 22 days
Weighted Average Remaining Life, Options exercisable at end of period	3 years 3 months 7 days
Aggregate Intrinsic Value
Outstanding aggregate intrinsic value	$ 4,446
Vested and expected to vest in the future, aggregate intrinsic value	4,208
Exercisable, aggregate intrinsic value	$ 989