Lease Commitments - Finance Lease Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing leases:
Non-utility property	$ 18,540	$ 10,028
Accumulated depreciation	(2,267)	(973)
Non-utility property, net	16,273	9,055
Other current liabilities	3,203	1,637
Other deferred credits	12,800	7,102
PNM
Financing leases:
Non-utility property	8,561	4,857
Accumulated depreciation	(1,070)	(482)
Non-utility property, net	7,491	4,375
Other current liabilities	1,512	722
Other deferred credits	5,699	3,333
TNMP
Financing leases:
Non-utility property	9,712	4,910
Accumulated depreciation	(1,137)	(466)
Non-utility property, net	8,575	4,444
Other current liabilities	1,623	850
Other deferred credits	$ 6,958	$ 3,597