Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Unrealized holding gains (losses) arising during the period, income tax (expense)	$ (2,679)	$ (1,332)
Reclassification adjustment for (gains) included in net earnings (loss), income tax expense	1,635	1,283
Pension liability adjustment, income tax (expense) benefit	(583)	(508)
Change in fair market value, income tax (expense)	0	53
Reclassification adjustment for (gains) losses included in net earnings (loss), income tax expense (benefit)	0	(19)
Public Service Company of New Mexico [Member]
Unrealized holding gains (losses) arising during the period, income tax (expense)	(2,679)	(1,332)
Reclassification adjustment for (gains) included in net earnings (loss), income tax expense	1,635	1,283
Pension liability adjustment, income tax (expense) benefit	(583)	(508)
Texas-New Mexico Power Company [Member]
Change in fair market value, income tax (expense)	0	53
Reclassification adjustment for (gains) losses included in net earnings (loss), income tax expense (benefit)	$ 0	$ (19)

Amount of tax (expense) benefit, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans, attributable to parent entity.

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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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