Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Tranches

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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-Publisher FASB
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-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ 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
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=109197908&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.

+ References

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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

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

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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

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

+ References

No definition available.

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- Definition

An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

+ 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
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- Definition

Percentage of vesting of share-based compensation awards.

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

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- Definition

Weighted average grant-date fair value of non-vested options outstanding.

+ References

No definition available.

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Stockholders' Equity - Co-Founder Grants and Award Modifications (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2017 USD ($) tranche $ / shares shares	Mar. 31, 2019 USD ($) $ / shares shares	Mar. 31, 2018 USD ($)	Dec. 31, 2018 shares	Dec. 31, 2017 USD ($) tranche $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share) \| $ / shares		$ 9.22
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)		2.3
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental stock based compensation \| $			$ 10.0
Co-Founder Grants \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	14.7	14.7		14.7
Expiration period	10 years
Number of tranches \| tranche	9				9
Weighted average grant date fair value (in dollars per share) \| $ / shares	$ 10.60				$ 10.60
Unamortized stock-based compensation, requisite service period					5 years 2 months 12 days
Remaining unamortized stock-based compensation \| $	$ 156.2	$ 119.3			$ 156.2
Stock-based compensation related to the Co-Founder Grants \| $		$ 8.6	$ 10.6
Co-Founder Grants \| Restricted Stock \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation, requisite service period					2 years 10 months 25 days
Co-Founder Grants \| Restricted Stock \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation, requisite service period					6 years 10 months 25 days
Co-Founder Grants \| Restricted Stock \| Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Co-Founder Grants \| Restricted Stock \| Tranche One \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage vested maximum	20.00%
Co-Founder Grants \| Chief Executive Officer \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	10.3
Co-Founder Grants \| Director \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	4.4