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Equity Incentive Plan - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Jun. 03, 2015	Apr. 22, 2005	Apr. 30, 2010	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2009	Dec. 31, 2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exchange for new stock option granted			4,369,000
Stock options exercise price			$ 1.47
Eligible stock options exchanged for new stock options granted			3,785,000
Stock Option Granted				0	0	0
Stock Option Granted Intrinsic Value				$ 580	$ 3,688	$ 1,565
Total unrecognized compensation cost related to non-vested share-based compensation				0
Cash received from employee toward stock option exercise				93	494	514
Tax effect for stock-based compensation benefit (expense) for option and restricted stock units exercised				$ 37	561	(24)
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option granted exercise price			$ 1.85
2005 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares for issuance upon exercise of stock options and restricted stock units		10,000,000					15,000,000	15,000,000
Conversion ratio of restricted stock unit to ordinary shares				One-for-one
2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares for issuance upon exercise of stock options and restricted stock units	20,000,000
Restricted Stock Units | The 2005 Plan and The 2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to non-vested share-based compensation				$ 5,719
Stock Options And Restricted Stock Units Exercised
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax effect for stock-based compensation benefit (expense) for option and restricted stock units exercised				$ 1,702	$ 1,647	$ 1,231

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Describe the conversion features of common stock if such stock is convertible. That is, shares of common stock into which another convertible security was converted, or shares of common stock into which another class of common stock was converted.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

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-Publisher FASB
-Name Accounting Standards Codification
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Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements.

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-Publisher FASB
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Unrecognized cost of unvested share-based compensation awards.

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Number of additional shares authorized for issuance under an established share-based compensation plan.

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Net number of share options (or share units) granted during the period.

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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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