Fair market value of common stock.

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- Definition

Share-based compensation arrangement by share-based payment award options minimum employee voting power ownership of all classes of stock to determine fair value.

+ References

No definition available.

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- Definition

Share-based compensation arrangement by share-based payment award percentage of forfeiture rate.

+ References

No definition available.

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- Definition

Share-based compensation arrangement by Share-based payment award unvested options exercises.

+ References

No definition available.

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- Definition

Shares of common stock reserved for issuance, automatic annual increase initiation date.

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No definition available.

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- Definition

Stock outstanding during period shares employee stock purchase plans.

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

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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

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

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- Definition

Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=SL79508275-113901

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- Definition

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
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-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=SL79508275-113901

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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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- Definition

General descriptive information regarding an arrangement under which employees and directors receive: (a) awards of equity shares, equity share options, or other equity instruments; or (b) the entity incurs liabilities to them: (1) in amounts based, at least in part, on the price of the entity's shares or other equity instruments; or (2) that require or may require settlement by issuance of the entity's shares. Such an arrangement is usually provided to employees and directors to compensate them, provide performance incentives to them, and to attract or retain their services. May also include pertinent information particular to a plan that is not elsewhere specified in the taxonomy.

+ 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)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901

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- Definition

Discount rate from fair value on offering date that participants pay for 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
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Discount rate from fair value on purchase date that participants pay for shares.

+ References

+ Details

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

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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.

+ Details

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- Definition

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

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

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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

+ Details

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- Definition

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

+ References

+ Details

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- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

+ References

No definition available.

+ Details

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- Definition

The number of employees affected by the modification of an equity-based compensation plan.

+ References

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- Definition

Description of pertinent provisions of equity-based compensation awards that have actual or potential impact upon the company's financial statements.

+ References

+ Details

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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

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- Definition

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

+ References

No definition available.

+ Details

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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=84159872&loc=d3e21463-112644

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(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: 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(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-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

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Equity Incentive Plans - Additional Information (Details)	1 Months Ended	12 Months Ended
	May 31, 2017 shares	Dec. 31, 2017 USD ($) Participant $ / shares shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($) shares	Jun. 30, 2017 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		2,813,593	6,890,085
Unvested options resulting from early exercises		0	0	0
Aggregate intrinsic value of options exercised \| $		$ 800,000	$ 23,000,000	$ 7,000,000
Total intrinsic value of all outstanding options \| $		15,900,000	2,500,000	100,000
Total unrecognized stock-based compensation cost related to unvested stock options \| $		$ 800,000	$ 200,000
Total unrecognized stock-based compensation cost related to unvested stock options, recognized ratably over a weighted-average period		3 years 2 months 12 days	3 years 2 months 12 days
Cash received from exercise of stock options \| $		$ 55,000	$ 25,000	$ 31,000
Income tax benefits from stock-based compensation \| $		$ 0
Percentage of forfeiture rate		0.00%	0.00%	0.00%
Restricted Stock Unit
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted		47,312
Minimum \| Restricted Stock Unit
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		7 months
Grant Date Fair Value, Granted \| $ / shares		$ 11.50
Maximum \| Restricted Stock Unit
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		10 months
Grant Date Fair Value, Granted \| $ / shares		$ 16.96
2017 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	2,413,659
Number of shares available for future grant	900,000	1,003,875
Shares of common stock reserved for issuance, automatic annual increase initiation date	Jan. 01, 2018
Percentage of number of shares of common stock outstanding			5.00%
Number of shares authorized for issuance					900,000
2017 Equity Incentive Plan \| Shares under 2005 Plan that would have otherwise been returned to 2005 Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	1,314,752
ISO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Ownership percentage, minimum		10.00%
ISO \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair value of common stock granted to employees		110.00%
2005 Plan and 2017 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
2005 Plan and 2017 Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period		10 years
2017 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		200,000
Number of shares available for future grant		150,000
Percentage of number of shares of common stock outstanding			2.00%
Percentage of fair market value of common stock on purchase date of the first day of IPO	85.00%
Percentage of fair market value of common stock on purchase date	85.00%
Purchase of common stock under ESPP, Description		The 2017 ESPP allows eligible employees to purchase shares of the Company’s common stock in an offering at a discount of the then-current trading price, up to the lesser of (1) 85% of the fair market value of the common stock on the first day of the IPO or (2) 85% of the fair market value of the common stock on the purchase date. The 2017 ESPP permits the maximum discounted purchase price permitted under U.S. tax rules, including a “lookback.”
Initial offering period in length		24 months
Number of participant have the right to purchase shares of common stock \| Participant		0
Fair Market Value Of Common Stock \| $		$ 25,000
Shares issued under ESPP		34,133
Shares outstanding under ESPP		34,133