Lease Commitments - Operating Lease Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Operating leases:
Operating lease assets, net of amortization	$ 62,440	$ 79,511
Current portion of operating lease liabilities	18,534	27,218
Long-term portion of operating lease liabilities	41,701	55,993
PNM
Operating leases:
Operating lease assets, net of amortization	58,670	73,903
Current portion of operating lease liabilities	16,902	25,278
Long-term portion of operating lease liabilities	39,754	52,552
TNMP
Operating leases:
Operating lease assets, net of amortization	3,769	5,264
Current portion of operating lease liabilities	1,631	1,882
Long-term portion of operating lease liabilities	$ 1,947	$ 3,155