Aggregate number of common shares reserved for future issuance.

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

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No definition available.

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

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- Definition

Number of new stock issued during the period.

+ 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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Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

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Stockholders' Equity - Incentive Plans and Equity Distribution Agreement (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Mar. 13, 2017	Dec. 31, 2015	Dec. 31, 2014	Jan. 01, 2017	Dec. 31, 2016	Dec. 31, 2013
Stock option and incentive plans
Aggregate net proceeds from shares sold		$ 28,136	$ 41,202
Equity Distribution Agreement
Stock option and incentive plans
Shares sold	1,669,092
Aggregate net proceeds from shares sold	$ 2,000
Stock option
Stock option and incentive plans
Outstanding (in shares)		1,799,226	1,670,574		2,239,044	1,093,208
2005 Plan
Stock option and incentive plans
Outstanding (in shares)					430,922
Common stock reserved for issuance (in shares)					0
2014 Plan
Stock option and incentive plans
Common stock reserved for issuance (in shares)				820,127	31,922
2014 Plan \| Stock option
Stock option and incentive plans
Outstanding (in shares)					1,808,122
2014 Plan \| Restricted stock
Stock option and incentive plans
Outstanding (in shares)					195,900