Unrecognized cost of unvested share-based compensation awards.

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)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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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.

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Unrecognized cost of unvested options awarded to employees as compensation.

+ References

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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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

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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- 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.

+ 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 (e)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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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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No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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- Definition

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

+ References

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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
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ 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 (d)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
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- Definition

Intrinsic value of equity-based compensation awards not vested. Excludes stock and unit options.

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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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
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Number of non-vested options outstanding.

+ References

No definition available.

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- Definition

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

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

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Share-based Compensation Arrangement by Share-based Payment Award, Provision for Number of Additional Shares Authorized, Percent

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Share-based Compensation Arrangement By Share-based Payment Award, Vesting Rights Percentage

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- Definition

Stock-based Compensation, Maximum Amount Deductible

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No definition available.

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Stock-Based Compensation - Narrative (Detail) - USD ($)		1 Months Ended	12 Months Ended
Stock-Based Compensation - Narrative (Detail) - USD ($)	Dec. 03, 2013	Jun. 30, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 04, 2013	Nov. 29, 2010	Dec. 31, 2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares)			3,285,000	2,714,000
Intrinsic value of options exercised			$ 24,000	$ 300,000	$ 300,000
Intrinsic value of restricted stock units, vested			$ 0	0	3,000,000
Weighted average remaining contractual term			1 year 2 months 12 days
Intristic value of restricted stock units, nonvested			$ 1,300,000
Stock-based compensation			$ 7,353,000	7,686,000	9,492,000
Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock options (in shares)			32,000
Unrecognized compensation expense			$ 300,000
Stock-based compensation			100,000	$ 200,000	$ (200,000)
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation costs			$ 9,400,000
Recognition over weighted average periods			2 years 4 months 1 day
Stock Options [Member] \| Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term			2 years 6 months
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares)			137,000
2006 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved								141,750
Expected term			10 years
2006 Plan [Member] \| Monthly Vesting Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage			2.08333%
2006 Plan [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term			4 years
2006 Plan [Member] \| Stock Options [Member] \| Annual Vesting Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage			25.00%
2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved							280,459
Expected term			10 years
Vesting term			4 years
2010 Plan [Member] \| Monthly Vesting Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage			2.08333%
2010 Plan [Member] \| Annual Vesting Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage			25.00%
Restated 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved		1,162,500	571,778	324,713
Percent of additional shares authorized provision		4.00%
Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved			236,625	202,230		337,500
Maximum amount deductible	$ 1,000,000
Purchase Plan [Member] \| Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved			147,576	151,490
Percentage of purchase price			85.00%
Maximum percentage of employee withholding			20.00%
Maximum number of shares per employee			2,500
Number of shares purchased during period			35,164	25,204	62,987