STOCKHOLDERS' EQUITY - Summary of Restricted Stock, Restricted Stock Unit and Performance Stock Unit Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) $ / shares shares
Weighted Average Grant Price
Outstanding, beginning balance (in USD per share) \| $ / shares	$ 4.49
Granted (in USD per share) \| $ / shares	8.97
Forfeited (in USD per share) \| $ / shares	5.40
Outstanding, ending balance (in USD per share) \| $ / shares	7.03
Weighted Average Grant Price, Unvested, Ending balance \| $ / shares	$ 7.76
Weighted Average Remaining Contractual Term, Outstanding	1 year 7 months 6 days
Weighted Average Remaining Contractual Term, Unvested	1 year 8 months 12 days
Aggregate Intrinsic Value, Outstanding, Ending balance \| $	$ 6,330
Aggregate Intrinsic Value, Unvested, Ending balance \| $	$ 6,593
Performance Stock Units
Weighted Average Grant Price
Attainment level percentage	100.00%
Additional issuance if performance targets met (in shares)	187
Restricted Stock, Restricted Stock Units and Performance Stock Units
Restricted Stock, Restricted Stock Units, and Performance Stock Units
Outstanding, beginning balance (in shares)	962
Granted (in shares)	608
Forfeited (in shares)	(18)
Outstanding, ending balance (in shares)	1,099
Expected to vest (in shares)	1,286
Class A Common Stock
Weighted Average Grant Price
Vested (in USD per share) \| $ / shares	$ 4.47
Class A Common Stock \| Restricted Stock, Restricted Stock Units and Performance Stock Units
Restricted Stock, Restricted Stock Units, and Performance Stock Units
Vested (in shares)	(453)

Intrinsic value of equity-based awards excluding options expected to vest.

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The number of equity-based awards other than stock options that are expected to vest.

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The weighted average fair value as of the grant date of equity-based awards other than stock options for awards that are expected to vest.

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMns' format, that are expected to vest.

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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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
-Topic 718
-SubTopic 10
-Section 50
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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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- Definition

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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- Definition

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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- Definition

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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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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- Definition

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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- Definition

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

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-Name Accounting Standards Codification
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- Definition

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

Percentage of vesting of share-based compensation awards.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options.

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