Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(4)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Represents the exercise price as a percentage of the fair market value of a single share of common stock on the date of grant.

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No definition available.

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The period of time from the grant date until the time at which the share-based award expires.

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Represents the number of shares originally approved (usually by shareholders and board of directors) for awards under the prior plan of equity based compensation transferred to the current plan.

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No definition available.

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Represents the number of shares reserved for issuance under stock plans that validly exist and are outstanding as of the balance sheet date.

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Represents the percentage of voting power in the entity's common stock required for a specified exercise price to be effective.

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No definition available.

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Represents the percentage of voting power in the entity's common stock required for a specified vesting period to be effective.

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COMMON STOCK AND STOCK INCENTIVE PLANS - Stock Incentive Plans (Details) - shares			12 Months Ended
	Jan. 04, 2016	Jul. 21, 2006	Dec. 31, 2017	Dec. 31, 2016	Nov. 04, 2016
2017 Equity Incentive Plan
Stock Incentive Plans
Number of shares authorized				2,000,000
Number of ordinary shares available for issuance pursuant to future grants			3,469,239	2,960,940	960,940
Number of shares transferred from the prior plan				960,940
Vesting period			4 years
2017 Equity Incentive Plan \| Stock Options and Restricted Stock Units RSU
Stock Incentive Plans
Number of awards outstanding (in shares)			1,165,623
2006 Equity Incentive Plan
Stock Incentive Plans
Number of shares authorized		1,500,000
Number of awards outstanding (in shares)				2,042,798
Number of shares expired				1,546,927
Number of ordinary shares available for issuance pursuant to future grants				1,022,114
Number of additional shares authorized	1,500,000
Number of shares transferred from the prior plan				8,474,347
Vesting period		4 years
2006 Equity Incentive Plan \| Employee and Directors Stock Options
Stock Incentive Plans
Expiration term				7 years
2006 Equity Incentive Plan \| Incentive Stock Option
Stock Incentive Plans
Expiration term				5 years
Percentage of voting power required of the company's stock for specified vesting period				10.00%
2006 Equity Incentive Plan \| Minimum \| Stock Options and Restricted Stock Units RSU
Stock Incentive Plans
Vesting period				1 year
2006 Equity Incentive Plan \| Minimum \| Employee and Directors Stock Options
Stock Incentive Plans
Exercise price as a percentage of the fair market value of an ordinary share on the date of grant				100.00%
2006 Equity Incentive Plan \| Maximum \| Stock Options and Restricted Stock Units RSU
Stock Incentive Plans
Vesting period				4 years
2006 Equity Incentive Plan \| Maximum \| Employee and Directors Stock Options
Stock Incentive Plans
Percentage of voting power required of the company's stock for specified exercise price				110.00%