Lease Commitments - Schedule of Supplemental Cash Flows Related to Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 27,849
Operating cash flows from financing leases	71
Finance cash flows from financing leases	313
Non-cash information related to right-of-use assets obtained in exchange for lease obligations:
Operating leases	157,816
Financing leases	9,645
Public Service Company of New Mexico
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	26,392
Operating cash flows from financing leases	44
Finance cash flows from financing leases	183
Non-cash information related to right-of-use assets obtained in exchange for lease obligations:
Operating leases	143,816
Financing leases	4,473
Texas-New Mexico Power Company
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	935
Operating cash flows from financing leases	25
Finance cash flows from financing leases	109
Non-cash information related to right-of-use assets obtained in exchange for lease obligations:
Operating leases	12,942
Financing leases	$ 4,910