Lease Commitments - Operating Lease Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Operating leases:
Operating lease assets, net of amortization	$ 52,675	$ 55,982
Current portion of operating lease liabilities	10,425	18,781
Long-term portion of operating lease liabilities	40,238	41,336
PNM
Operating leases:
Operating lease assets, net of amortization	49,732	52,556
Current portion of operating lease liabilities	9,191	17,239
Long-term portion of operating lease liabilities	38,759	39,633
TNMP
Operating leases:
Operating lease assets, net of amortization	2,943	3,426
Current portion of operating lease liabilities	1,234	1,543
Long-term portion of operating lease liabilities	$ 1,479	$ 1,703