Aggregate number of common shares reserved for future issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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Stockholders' Equity - Incentive Plans (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019	Dec. 31, 2017
Stock options
Stock option and incentive plans
Granted (in shares)	4,703,000	1,372,000
Outstanding (in shares)	8,540,281	4,951,409		3,754,320
2005 Plan
Stock option and incentive plans
Common stock reserved for issuance (in shares)	0
2005 Plan \| Stock options
Stock option and incentive plans
Outstanding (in shares)	330,450
2014 Plan
Stock option and incentive plans
Common stock reserved for issuance (in shares)	663,460		5,082,305
2014 Plan \| Stock options
Stock option and incentive plans
Outstanding (in shares)	7,121,331
2014 Plan \| Restricted stock
Stock option and incentive plans
Outstanding (in shares)	32,400
Outside of 2014 Plan \| Stock options
Stock option and incentive plans
Granted (in shares)	920,000	311,000