Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Cash, Cash Equivalents, and Restricted Cash

The following table presents the components of total cash, cash equivalents, and restricted cash on the consolidated balance sheets.

(In thousands)	MGE Energy				MGE
As of December 31,	2023		2022		2023		2022
Cash and cash equivalents	$	11,140	$	11,604	$	2,819	$	4,136
Restricted cash		858		867		858		867
Receivable - margin account		3,028		5,497		3,028		5,497
Cash, cash equivalents, and restricted cash	$	15,026	$	17,968	$	6,705	$	10,500

Straight-Line Depreciation Rates

Provisions at composite straight-line depreciation rates approximate the following percentages for the cost of depreciable property:

	2023		2022		2021
Electric(a)	3.8	%	3.2	%	3.2	%
Gas	2.1	%	2.1	%	2.2	%
Nonregulated	2.3	%	2.3	%	2.4	%

(a)In the 2023 limited reopener, the PSCW approved new depreciation rates for Columbia effective January 1, 2023.

Approved AFUDC retail rates by rate case

For 2023, 2022, and 2021, as approved by the PSCW, MGE capitalized AFUDC-debt and equity on 50% of applicable average construction work in progress as shown in the following table:

	2023		2022		2021
Approved AFUDC retail rates	7.11	%	7.11	%	6.89	%

Approved AFUDC-debt and equity capitalized amounts

For the years ended 2023, 2022, and 2021, MGE recorded AFUDC-debt and AFUDC-equity as shown in the following table:

(In millions)	2023		2022		2021
AFUDC-debt	$	2.0	$	1.1	$	1.7
AFUDC-equity	$	5.8	$	3.0	$	5.0