Common Stock [Line Items]

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- Definition

Number of shares of Common Stock approved for cancellation by the Board of Directors

+ References

No definition available.

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- Definition

Proceeds from issuance of common stock, authorization requested from regulatory agency for public utilities

+ References

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- Definition

Under the Merger Agreement the Maximum amount of dividends declared during the period for each share of common stock outstanding before June 1, 2020.

+ References

No definition available.

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- Definition

Under the Merger Agreement the Maximum amount of dividends declared during the period for each share of common stock outstanding on or after June 1, 2020.

+ References

No definition available.

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- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, 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
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-Section 50
-Paragraph 2
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- Definition

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Dec. 27, 2019	Jan. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 23, 2019	May 29, 2014
Common Stock [Line Items]
Dividends, Common Stock, Cash	$ 15,700		$ 61,718	$ 57,539	$ 53,337
Number of shares of Common Stock approved for cancellation by the Board of Directors						1,400,000
Under the Merger Agreement Max dividends declared per share before June 1, 2020			$ 0.385
Under the Merger Agreement Max dividends declared per share on or after June 1, 2020.			0.41
Common Stock, Par or Stated Value Per Share			$ 1	$ 1
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized							1,700,000
Restricted Stock \| Minimum
Common Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period			1 year
Restricted Stock \| Maximum
Common Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period			3 years
NMPRC Case No. 19-00033-UT \| Maximum
Common Stock [Line Items]
Proceeds from issuance of common stock, requested		$ 200,000
FERC \| Maximum
Common Stock [Line Items]
Proceeds from issuance of common stock, requested		$ 200,000