Employee Benefit Plans - Status of Stock Options Related to Stock Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Outstanding Beginning Balance	714,000
Options Outstanding Exercised	(15,000)
Options Outstanding Forfeited	(260,000)
Options Outstanding Ending Balance	439,000	714,000
Options Outstanding Exercisable	439,000
Weighted Average Exercise Price Per Share, Beginning Balance	$ 17.56
Weighted Average Exercise Price Per Share, Exercised	1.81
Weighted Average Exercise Price Per Share, Forfeited	25.44
Weighted Average Exercise Price Per Share, Ending Balance	13.42	$ 17.56
Weighted Average Exercise Price Per Share, Exercisable	$ 13.42
Weighted Average Remaining Contractual Term	1 year 4 months 24 days	1 year 7 months 6 days
Weighted Average Remaining Contractual Term, Exercisable	1 year 4 months 24 days
Aggregate Intrinsic Value, Beginning Balance	$ 5,327	$ 5,605
Aggregate Intrinsic Value, Exercisable	5,327
Intrinsic value of stock options exercised	$ 250	$ 2,511	$ 1,187
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Per Share, Beginning Balance	$ 1.81
Exercise Price Per Share, Exercised	1.81
Exercise Price Per Share, Forfeited	23.30
Exercise Price Per Share, Ending Balance	1.81	$ 1.81
Exercise Price Per Share, Exercisable	1.81
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price Per Share, Beginning Balance	30.07
Exercise Price Per Share, Exercised	1.81
Exercise Price Per Share, Forfeited	26.42
Exercise Price Per Share, Ending Balance	30.07	$ 30.07
Exercise Price Per Share, Exercisable	$ 30.07

Share based compensation shares authorized under stock option plans exercisable exercise price range lower range limit.

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Share based compensation shares authorized under stock option plans exercised exercise price range lower range limit.

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Share based compensation shares authorized under stock option plans forfeited exercise price range lower range limit.

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Share based compensation shares authorized under stock option plans outstanding exercise price range.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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As of the balance sheet date, the weighted-average exercise price (at which grantees can acquire the shares reserved for issuance) for exercisable stock options that are fully vested or expected to vest.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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