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=120391452&loc=d3e13212-122682

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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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

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

+ 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)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&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)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ 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

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=120381028&loc=d3e5070-113901

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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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Shareholders' Equity - Plan Summary and Description (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted Stock
Information pertaining to stock based awards
Outstanding awards issued (in shares)	0	0	100,000	300,000
RSUs
Information pertaining to stock based awards
Outstanding awards issued (in shares)	1,800,000	1,200,000	1,300,000	1,600,000
SSAR Awards
Information pertaining to stock based awards
Outstanding awards issued (in shares)	2,300,000	2,200,000	1,500,000	700,000
2016 Plan
Information pertaining to stock based awards
Exercisable period	7 years
Common stock authorized for issuance (in shares)	2,500,000
Remaining shares of common stock available for future issuance (in shares)	700,000
2016 Plan \| Restricted Stock
Information pertaining to stock based awards
Outstanding awards issued (in shares)	0
2016 Plan \| RSUs
Information pertaining to stock based awards
Outstanding awards issued (in shares)	1,500,000
2016 Plan \| SSAR Awards
Information pertaining to stock based awards
Outstanding awards issued (in shares)	2,200,000
2006 Plan
Information pertaining to stock based awards
Common stock subject to outstanding awards (in shares)	4,200,000
Remaining shares of common stock available for future issuance (in shares)	0
2006 Plan \| Restricted Stock
Information pertaining to stock based awards
Outstanding awards issued (in shares)	0
2006 Plan \| RSUs
Information pertaining to stock based awards
Outstanding awards issued (in shares)	400,000
2006 Plan \| SSAR Awards
Information pertaining to stock based awards
Outstanding awards issued (in shares)	100,000