Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unrealized holding gains (losses) arising during the period, income tax (expense)	$ (4,310)	$ (6,812)	$ (10,855)
Reclassification adjustment for (gains) included in net earnings (loss), income tax expense	11,181	5,461	4,734
Experience gain (loss), income tax (expense) benefit	1,726	6,024	(6,781)
Reclassification adjustment for amortization of experience (gain) loss recognized as net periodic benefit cost, income tax (expense) benefit	(2,332)	(2,032)	(2,524)
Change in fair market value, income tax (expense)	(28)	53	98
Reclassification adjustment for (gains) losses included in net earnings (loss), income tax expense (benefit)	0	(195)	(73)
Public Service Company of New Mexico [Member]
Unrealized holding gains (losses) arising during the period, income tax (expense)	(4,310)	(6,812)	(10,855)
Reclassification adjustment for (gains) included in net earnings (loss), income tax expense	11,181	5,461	4,734
Experience gain (loss), income tax (expense) benefit	1,726	6,024	(6,781)
Reclassification adjustment for amortization of experience (gain) loss recognized as net periodic benefit cost, income tax (expense) benefit	(2,332)	(2,032)	(2,524)
Texas-New Mexico Power Company [Member]
Change in fair market value, income tax (expense)	0	53	98
Reclassification adjustment for (gains) losses included in net earnings (loss), income tax expense (benefit)	$ 0	$ (195)	$ (73)