Nature of Business and Summary of Significant Accounting Policies (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011 Product Year Segment
Significant Accounting Policies [Line Items]
Number of product candidates under development	3
Property and equipment, useful life minimum	3
Property and equipment, useful life maximum	10
Capitalized costs, amortization period maximum	17
Tax benefit, minimum percentage of likelihood of being realized upon ultimate settlement	50.00%
Deferred executive compensation plan, vesting period	4 years
Accrued rent	$ 1.7
Number of operating segments	1

Deferred Executive Compensation plan vesting period.

No definition available.

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- Definition

Represents minimum percentage of likelihood of tax benefit being realized upon ultimate settlement.

+ References

No definition available.

+ Details

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- Definition

Number of operating segments.

+ References

No definition available.

+ Details

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- Definition

Represents number of product candidates currently under development.

+ References

No definition available.

+ Details

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- Details

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and due after one year (or beyond the operating cycle if longer) for contractual rent under lease arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 24

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The maximum useful life of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 35

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6904245&loc=d3e15217-109273

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 35

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6904245&loc=d3e15300-109273

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 35

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6904245&loc=d3e15211-109273

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- Definition

The maximum useful life of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References

No definition available.

+ Details

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- Definition

The minimum useful life of long lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References

No definition available.

+ Details

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