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Stock Option Rollforward Table (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Text Block [Abstract]
Beginning outstanding, shares	395,353	540,441	540,441
Ending outstanding, shares	351,561	395,353	540,441
Exercised	(43,792)	(145,088)	0
Beginning outstanding, Weighted-average Exercise Price	$ 96.37	$ 96.35	$ 96.35
Weighted Average Exercise Price	91.60	96.27	0
Ending outstanding, Weighted-average Exercise Price	$ 96.97	$ 96.37	$ 96.35

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- Definition

Exercised Weighted Averge Exercise Price

+ References

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Stock Issued During Period Shares Stock Options Exercise

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ 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

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

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option 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)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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