Regulatory Matters (Tables)

3 Months Ended

Mar. 31, 2020

Regulated Operations [Abstract]

Regulatory Assets and Liabilities [Table Text Block]

Regulatory Assets and Liabilities	March 31, 2020		December 31, 2019
Millions
Non-Current Regulatory Assets
Defined Benefit Pension and Other Postretirement Benefit Plans		$211.1		$212.9
Income Taxes	121.0		123.4
Cost Recovery Riders	34.1		24.7
Asset Retirement Obligations	31.8		32.0
Boswell Units 1 and 2 Net Plant and Equipment	9.3		10.7
Manufactured Gas Plant	8.3		8.2
PPACA Income Tax Deferral	4.7		4.8
Other	3.5		3.8
Total Non-Current Regulatory Assets		$423.8		$420.5
Current Regulatory Liabilities (a)
Transmission Formula Rates Refund		$1.3		$1.7
Provision for Tax Reform Refund	0.2		0.2
Total Current Regulatory Liabilities	1.5		1.9
Non-Current Regulatory Liabilities
Income Taxes	397.1		407.2
Wholesale and Retail Contra AFUDC	84.2		79.3
Plant Removal Obligations	37.4		35.5
Defined Benefit Pension and Other Postretirement Benefit Plans	15.6		17.0
North Dakota Investment Tax Credits	12.3		12.3
Fuel Adjustment Clause (b)	8.4		—
Conservation Improvement Program	7.4		5.4
Other	4.0		3.6
Total Non-Current Regulatory Liabilities	566.4		560.3
Total Regulatory Liabilities		$567.9		$562.2

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

(b)

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.)