Collaborative Arrangement, Owner Obligations, Default, Amount

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- Definition

Public Utilities, Contribution to Construction Activities

+ References

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- Definition

Public Utilities, Ownership Percentage

+ References

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- Definition

Public Utilities, Renewable Energy Under Contract

+ 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.

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- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ 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
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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- Definition

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

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Significant Accounting Policies and Responsibility for Financial Statements (Details)	1 Months Ended				3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) $ / shares MW	Jul. 31, 2019 $ / shares	Sep. 30, 2018 $ / shares	Jul. 31, 2018 $ / shares	Sep. 30, 2019 USD ($) $ / shares MW	Sep. 30, 2018 USD ($) $ / shares	Sep. 30, 2019 USD ($) $ / shares MW	Sep. 30, 2018 USD ($) $ / shares
Business Acquisition [Line Items]
Payment defaults under agreements	$ 0				$ 0		$ 0
Dividends declared per common share (dollars per share) \| $ / shares	$ 0.290	$ 0.290	$ 0.265	$ 0.265	$ 0.290	$ 0.265	$ 0.870	$ 0.795
Dividends declared on common stock					$ 46,200,000	$ 42,217,000	$ 69,299,000	$ 63,325,000
NMRD
Business Acquisition [Line Items]
Renewable energy capacity in operating (in mw) \| MW	35.1				35.1		35.1
Texas-New Mexico Power Company
Business Acquisition [Line Items]
Dividends declared on common stock					$ 15,367,000	$ 15,368,000	$ 30,178,000	25,804,000
PNMR Development \| NMRD
Business Acquisition [Line Items]
Ownership percentage	50.00%				50.00%		50.00%
AEP OnSite Partners \| NMRD
Business Acquisition [Line Items]
Ownership percentage	50.00%				50.00%		50.00%
PNMR Development and AEP OnSite \| NMRD
Business Acquisition [Line Items]
Contribution to construction activities							$ 29,300,000	$ 9,000,000.0