Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options for every share issued		1.75
Percentage of fair market value on the purchase date		85.00%
Maximum number of shares per employee		2,000
Employee stock purchase plan offering period		6 months
Maximum value of shares per employee		$ 25,000
Common stock reserved for issuance		1,000,000
Shares purchased by employee since inception of ESPP		581,451
Shares purchased under ESPP	17,670	23,713
Unrecognized compensation cost		$ 8,600,000
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)		3 years 5 months 1 day
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award vesting period (years)		4 years
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award expiration period (years)		5 years
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based payment award expiration period (years)		10 years
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
Restricted Stock Units
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 14 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 8 months 26 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

No definition available.

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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

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-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.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

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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.

+ References

No definition available.

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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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-Publisher FASB

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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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-Section 50

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- Definition

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

+ References

No definition available.

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