Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Unrealized holding gains (losses) arising during the period, income tax (expense)	$ (304)	$ (4,310)	$ (6,812)
Reclassification adjustment for (gains) included in net earnings (loss), income tax expense	8,639	11,181	5,461
Experience gain (loss), income tax (expense) benefit	7,219	1,726	6,024
Reclassification adjustment for amortization of experience (gain) loss recognized as net periodic benefit cost, income tax (expense) benefit	(2,148)	(2,332)	(2,032)
Change in fair market value, income tax (expense)	341	(28)	53
Reclassification adjustment for (gains) losses included in net earnings (loss), income tax expense (benefit)	(298)	0	(195)
Public Service Company of New Mexico [Member]
Unrealized holding gains (losses) arising during the period, income tax (expense)	(304)	(4,310)	(6,812)
Reclassification adjustment for (gains) included in net earnings (loss), income tax expense	8,639	11,181	5,461
Experience gain (loss), income tax (expense) benefit	7,219	1,726	6,024
Reclassification adjustment for amortization of experience (gain) loss recognized as net periodic benefit cost, income tax (expense) benefit	(2,148)	(2,332)	(2,032)
Texas-New Mexico Power Company [Member]
Change in fair market value, income tax (expense)	0	0	53
Reclassification adjustment for (gains) losses included in net earnings (loss), income tax expense (benefit)	$ 0	$ 0	$ (195)