Fair Value of Derivative and Other Financial Instruments, Debt Maturities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014
PNMR and PNM [Member]
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Available-for-sale debt securities, Within 1 year	$ 2,911
Available-for-sale debt securities, After 1 year through 5 years	21,556
Available-for-sale debt securities, After 5 years through 10 years	10,875
Available-for-sale debt securities, After 10 years through 15 years	9,114
Available-for-sale debt securities, After 15 years through 20 years	11,431
Available-for-sale debt securities, After 20 years	41,293
Available-for-sale debt securities	97,180
PNM Resources [Member]
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Held-to-maturity debt securities, Due within 1 year	12,017
Held-to-maturity debt securities, After 1 year through 5 years	33,776
Held-to-maturity debt securities, After 5 years through 10 years	0
Held-to-maturity debt securities	45,793
Public Service Company of New Mexico [Member]
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Held-to-maturity debt securities, Due within 1 year	12,017
Held-to-maturity debt securities, After 1 year through 5 years	33,050
Held-to-maturity debt securities, After 5 years through 10 years	0
Held-to-maturity debt securities	$ 45,067