STOCK-BASED COMPENSATION - SCHEDULE OF RESTRICTED STOCK UNITS AND RESTRICTED STOCK AWARDS (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
RSUs outstanding
Number of Restricted Stock Units/ Awards
Beginning outstanding balance (in shares)	1,091
Granted (in shares)	458
Released (in shares)	(698)
Forfeited (in shares)	(50)
Ending outstanding balance (in shares)	801	1,091
Weighted Average Grant Date Fair Value
Weighted average grant date fair value, beginning of period (in dollars per share)	$ 10.97
Weighted average fair value on grant date, granted (in dollars per share)	9.50
Weighted average fair value on grant date, released (in dollars per share)	11.38
Weighted average fair value on grant date, forfeited (in dollars per share)	9.89
Weighted average grant date fair value, end of period (in dollars per share)	$ 9.84	$ 10.97
Weighted average remaining service, options outstanding	1 year 8 months 16 days	8 months 1 day
Aggregate intrinsic value, options outstanding	$ 6,754	$ 9,773
RSAs outstanding
Number of Restricted Stock Units/ Awards
Beginning outstanding balance (in shares)	55
Granted (in shares)	8
Released (in shares)	0
Forfeited (in shares)	0
Ending outstanding balance (in shares)	63	55
Weighted Average Grant Date Fair Value
Weighted average grant date fair value, beginning of period (in dollars per share)	$ 13.02
Weighted average fair value on grant date, granted (in dollars per share)	9.94
Weighted average fair value on grant date, released (in dollars per share)	0.00
Weighted average fair value on grant date, forfeited (in dollars per share)	0.00
Weighted average grant date fair value, end of period (in dollars per share)	$ 12.63	$ 13.02
Weighted average remaining service, options outstanding	2 months 24 days	5 months 16 days

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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- Definition

Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options.

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