Aggregate number of common shares reserved for future issuance for ESPP.

No definition available.

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- Definition

Share based compensation arrangement by share based payment award performance period.

+ References

No definition available.

+ Details

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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
-Subparagraph (a)(1)
-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

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

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

+ 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

Percentage of vesting of share-based compensation awards.

+ References

+ Details

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Stock-Based Compensation - Additional Information (Details) - $ / shares	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share units performance period	3 years
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for issuance under ESPP	21,000
Employee Stock Purchase Plan \| Scenario Forecast
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for issuance under ESPP		36,000
PSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of share units granted	780,000
Weighted-average grant-date fair value	$ 27.41
PSUs \| Certain Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of share units granted	632,000
PSUs \| Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share units performance period	3 years
Award vesting period	3 years
PSUs \| Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share units performance period	2 years
Award vesting period	3 years
PSUs \| Minimum \| Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share units vesting percentage	0.00%
PSUs \| Minimum \| Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share units vesting percentage	0.00%
PSUs \| Maximum \| Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share units vesting percentage	150.00%
PSUs \| Maximum \| Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share units vesting percentage	200.00%
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of share units granted	519,000
Weighted-average grant-date fair value	$ 26.74
RSUs \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period	1 year
RSUs \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period	4 years