Regulatory Matters (Tables)

6 Months Ended

Jun. 30, 2020

Regulated Operations [Abstract]

Regulatory Assets and Liabilities [Table Text Block]

Regulatory Assets and Liabilities	June 30, 2020	December 31, 2019
Millions
Non-Current Regulatory Assets
Defined Benefit Pension and Other Postretirement Benefit Plans	$208.0	$212.9
Income Taxes	122.1	123.4
Cost Recovery Riders	39.3	24.7
Asset Retirement Obligations	31.7	32.0
Manufactured Gas Plant	8.3	8.2
Boswell Units 1 and 2 Net Plant and Equipment	7.8	10.7
PPACA Income Tax Deferral	4.7	4.8
Other	2.8	3.8
Total Non-Current Regulatory Assets	$424.7	$420.5
Current Regulatory Liabilities (a)
Provision for Interim Rate Refund (b)	$11.7	—
Transmission Formula Rates Refund	0.8	$1.7
Other	1.7	0.2
Total Current Regulatory Liabilities	14.2	1.9
Non-Current Regulatory Liabilities
Income Taxes	395.5	407.2
Wholesale and Retail Contra AFUDC	87.4	79.3
Plant Removal Obligations	39.3	35.5
Defined Benefit Pension and Other Postretirement Benefit Plans	14.1	17.0
North Dakota Investment Tax Credits	12.2	12.3
Fuel Adjustment Clause (c)	12.2	—
Conservation Improvement Program	5.4	5.4
Other	3.5	3.6
Total Non-Current Regulatory Liabilities	569.6	560.3
Total Regulatory Liabilities	$583.8	$562.2

(a)Current regulatory liabilities are presented within Other Current Liabilities on the Consolidated Balance Sheet.

(b)Provision for Interim Rate Refund represents reserves for interim rates resulting from the MPUC’s approval of Minnesota Power’s petition and proposal to resolve and withdraw its rate case. This amount is expected to be refunded to Minnesota Power regulated retail customers in the third quarter of 2020. (See 2020 Minnesota General Rate Case.)

(c)Fuel adjustment clause regulatory liability represents the amount expected to be refunded to customers for the over-collection of fuel adjustment clause recoveries. (See Fuel Adjustment Clause Reform.)