Regulatory and Rate Matters (Tables)

9 Months Ended

Sep. 30, 2020

Regulated Operations [Abstract]

Schedule of Rate Increases for Transmission Costs

The following sets forth TNMP’s recent interim transmission cost rate increases:

Effective Date	Approved Increase in Rate Base		Annual Increase in Revenue
	(In millions)
March 21, 2019	$	111.8	$	14.3
September 19, 2019	21.9		3.3
March 27, 2020	59.2		7.8
October 7, 2020	10.8		2.0