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Fair Value of Derivative and Other Financial Instruments - Maturities of Debt Securities (Details) - PNMR and PNM $ in Thousands	Sep. 30, 2021 USD ($)
Available-for-Sale
Within 1 year	$ 26,085
After 1 year through 5 years	77,703
After 5 years through 10 years	93,532
After 10 years through 15 years	21,475
After 15 years through 20 years	13,858
After 20 years	33,306
Available-for-sale debt securities	$ 265,959

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- Definition

Available-for-sale Securities, Debt Maturities, after Fifteen Years Through Twenty Years, Fair Value

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