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Pension and Other Postretirement Benefits Other Postretirement Benefits (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Other Retirement Plans, 401 (k) plan [Member] |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
401(k) plan | $ 16,725 | $ 16,703 | $ 16,785
Other Retirement Plans, 401 (k) plan [Member] | Public Service Company of New Mexico [Member] |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
401(k) plan | 12,679 | 12,745 | 12,952
Other Retirement Plans, 401 (k) plan [Member] | Texas-New Mexico Power Company [Member] |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
401(k) plan | 4,046 | 3,958 | 3,953
Other Retirement Plans, Key Employees, Non-qualified Plan [Member] |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
Non-qualified plan | 1,436 | 2,257 | 2,204
Other Retirement Plans, Key Employees, Non-qualified Plan [Member] | Public Service Company of New Mexico [Member] |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
Non-qualified plan | 1,090 | 1,722 | 1,691
Other Retirement Plans, Key Employees, Non-qualified Plan [Member] | Texas-New Mexico Power Company [Member] |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
Non-qualified plan | $ 346 | $ 535 | $ 513

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- Definition The compensation expense recognized during the period pertaining to the deferred compensation arrangement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 710 -SubTopic 10 -Section 30 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363 + Details
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- Definition The amount of the cost recognized during the period for defined contribution plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
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