Lease Commitments - Schedule of Future Expected Lease Payments (Details) $ in Thousands	Sep. 30, 2020 USD ($)
Financing
Remainder of 2020	$ 1,097
2021	4,304
2022	4,155
2023	3,869
2024	2,863
Later years	3,717
Total minimum lease payments	20,005
Less: Imputed interest	1,573
Lease liabilities as of September 30, 2020	18,432
Operating
Remainder of 2020	1,253
2021	29,294
2022	28,452
2023	19,395
2024	8,833
Later years	35,489
Total minimum lease payments	122,716
Less: Imputed interest	13,957
Lease liabilities as of September 30, 2020	108,759
PNM
Financing
Remainder of 2020	511
2021	2,011
2022	1,959
2023	1,899
2024	1,277
Later years	1,739
Total minimum lease payments	9,396
Less: Imputed interest	668
Lease liabilities as of September 30, 2020	8,728
Operating
Remainder of 2020	438
2021	26,576
2022	26,266
2023	17,735
2024	7,908
Later years	34,467
Total minimum lease payments	113,390
Less: Imputed interest	12,856
Lease liabilities as of September 30, 2020	100,534
TNMP
Financing
Remainder of 2020	565
2021	2,210
2022	2,115
2023	1,926
2024	1,583
Later years	1,977
Total minimum lease payments	10,376
Less: Imputed interest	898
Lease liabilities as of September 30, 2020	9,478
Operating
Remainder of 2020	682
2021	2,426
2022	1,975
2023	1,481
2024	877
Later years	765
Total minimum lease payments	8,206
Less: Imputed interest	554
Lease liabilities as of September 30, 2020	$ 7,652

Finance Lease, Liability, to be Paid, after Year Four

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Lessee, Operating Lease, Liability, to be Paid, after Year Four

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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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Amount of lessee's undiscounted obligation for lease payments for finance lease.

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in remainder of current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

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Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for finance lease.

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Amount of lessee's undiscounted obligation for lease payment for operating lease.

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease having initial or remaining lease term in excess of one year to be paid in remainder of current fiscal year.

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Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

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Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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