STOCK-BASED COMPENSATION - ADDITIONAL INFORMATION (Detail) - USD ($)	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options for every share issued (in shares)	1.75
Percentage of fair market value on the purchase date	85.00%
Maximum number of shares per employee (in shares)	2,000
Employee stock purchase plan offering period	6 months
Maximum value of shares per employee	$ 25,000
Common stock reserved for issuance (in shares)	1,000,000
Shares purchased by employee since inception of ESPP (in shares)	621,269
Shares purchased under ESPP (in shares)	17,711	23,713
Unrecognized compensation cost	$ 8,300,000
Outstanding stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award vesting period (years)	4 years
Outstanding stock options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award expiration period (years)	7 years
Outstanding stock options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award expiration period (years)	10 years
Unvested restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award vesting period (years)	1 year
Unrecognized compensation cost, recognized over an estimated weighted-average period (years)	11 months 4 days
Unvested RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award vesting period (years)	3 years
Unrecognized compensation cost, recognized over an estimated weighted-average period (years)	2 years 1 month 9 days
Standard Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, recognized over an estimated weighted-average period (years)	2 years 7 months 13 days
Market Condition Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, recognized over an estimated weighted-average period (years)	2 years 9 months 3 days

The reduction in number of available shares when a share is issued under the share based compensation.

No definition available.

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- Definition

The highest value of shares that an employee can purchase under the plan per period.

+ References

No definition available.

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- Definition

The offering period of the employee stock purchase plan ("ESPP").

+ References

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- Definition

The number of shares purchased by employees since inception of ESPP.

+ References

No definition available.

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ 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 (i)
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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

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.

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- Definition

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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- Definition

The highest quantity of shares an employee can purchase under the plan per period.

+ 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

The number of shares purchased on the open market during the period for issuance to employees under the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

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