Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2016

Regulated Operations [Abstract]

Regulatory Assets [Table Text Block]

Regulatory Assets and Liabilities
As of December 31	2016		2015
Millions
Current Regulatory Assets (a)
Deferred Fuel Adjustment Clause		$18.6		$10.6
Total Current Regulatory Assets	18.6		10.6
Non-Current Regulatory Assets
Defined Benefit Pension and Other Postretirement Benefit Plans (b)	226.1		219.3
Income Taxes (c)	63.3		64.2
Cost Recovery Riders (d)	30.5		58.0
Asset Retirement Obligations (e)	26.0		21.6
PPACA Income Tax Deferral	5.0		5.0
Other	8.7		3.9
Total Non-Current Regulatory Assets	359.6		372.0
Total Regulatory Assets		$378.2		$382.6
Non-Current Regulatory Liabilities
Wholesale and Retail Contra AFUDC (f)		$56.8		$58.0
North Dakota Investment Tax Credits (g)	28.2		12.8
Income Taxes (c)	19.1		6.1
Plant Removal Obligations	19.1		22.1
Defined Benefit Pension and Other Postretirement Benefit Plans (b)	—		0.9
Other	2.6		5.1
Total Non-Current Regulatory Liabilities		$125.8		$105.0

(a) Current regulatory assets are presented within Prepayments and Other on the Consolidated Balance Sheet.

(b) Defined benefit pension and other postretirement items included in our Regulated Operations, which are otherwise required to be recognized in accumulated other comprehensive income as actuarial gains and losses as well as prior service costs and credits, are recognized as regulatory assets or regulatory liabilities on the Consolidated Balance Sheet. The asset or liability will decrease as the deferred items are amortized and recognized as components of net periodic benefit cost. (See Note 15. Pension and Other Postretirement Benefit Plans.)

(c) These costs represent the difference between deferred income taxes recognized for financial reporting purposes and amounts previously billed to our customers. This balance will decrease over the remaining life of the related temporary differences and flow through current income taxes.

(d) The cost recovery rider regulatory assets are revenues not yet collected from our customers primarily due to capital expenditures related to Bison, investment in CapX2020 projects, and the Boswell Unit 4 environmental upgrade and are recognized in accordance with the accounting standards for alternative revenue programs. The cost recovery rider regulatory assets as of December 31, 2016, will be recovered within the next two years.

(e) Asset retirement obligations will accrete and be amortized over the lives of the related property with asset retirement obligations.

(f) Wholesale and Retail Contra AFUDC represents amortization to offset AFUDC Equity and Debt recorded during the construction period of our cost recovery rider projects prior to placing the projects in service. The regulatory liability will decrease over the remaining depreciable life of the related asset.

(g) North Dakota investment tax credits expected to be realized from Bison that will be credited to Minnesota Power’s regulated retail customers over the remaining life of Bison through future renewable cost recovery rider fillings.

Regulatory Liabilities [Table Text Block]

Regulatory Assets and Liabilities
As of December 31	2016		2015
Millions
Current Regulatory Assets (a)
Deferred Fuel Adjustment Clause		$18.6		$10.6
Total Current Regulatory Assets	18.6		10.6
Non-Current Regulatory Assets
Defined Benefit Pension and Other Postretirement Benefit Plans (b)	226.1		219.3
Income Taxes (c)	63.3		64.2
Cost Recovery Riders (d)	30.5		58.0
Asset Retirement Obligations (e)	26.0		21.6
PPACA Income Tax Deferral	5.0		5.0
Other	8.7		3.9
Total Non-Current Regulatory Assets	359.6		372.0
Total Regulatory Assets		$378.2		$382.6
Non-Current Regulatory Liabilities
Wholesale and Retail Contra AFUDC (f)		$56.8		$58.0
North Dakota Investment Tax Credits (g)	28.2		12.8
Income Taxes (c)	19.1		6.1
Plant Removal Obligations	19.1		22.1
Defined Benefit Pension and Other Postretirement Benefit Plans (b)	—		0.9
Other	2.6		5.1
Total Non-Current Regulatory Liabilities		$125.8		$105.0

(a) Current regulatory assets are presented within Prepayments and Other on the Consolidated Balance Sheet.

(b) Defined benefit pension and other postretirement items included in our Regulated Operations, which are otherwise required to be recognized in accumulated other comprehensive income as actuarial gains and losses as well as prior service costs and credits, are recognized as regulatory assets or regulatory liabilities on the Consolidated Balance Sheet. The asset or liability will decrease as the deferred items are amortized and recognized as components of net periodic benefit cost. (See Note 15. Pension and Other Postretirement Benefit Plans.)

(c) These costs represent the difference between deferred income taxes recognized for financial reporting purposes and amounts previously billed to our customers. This balance will decrease over the remaining life of the related temporary differences and flow through current income taxes.

(d) The cost recovery rider regulatory assets are revenues not yet collected from our customers primarily due to capital expenditures related to Bison, investment in CapX2020 projects, and the Boswell Unit 4 environmental upgrade and are recognized in accordance with the accounting standards for alternative revenue programs. The cost recovery rider regulatory assets as of December 31, 2016, will be recovered within the next two years.

(e) Asset retirement obligations will accrete and be amortized over the lives of the related property with asset retirement obligations.

(f) Wholesale and Retail Contra AFUDC represents amortization to offset AFUDC Equity and Debt recorded during the construction period of our cost recovery rider projects prior to placing the projects in service. The regulatory liability will decrease over the remaining depreciable life of the related asset.

(g) North Dakota investment tax credits expected to be realized from Bison that will be credited to Minnesota Power’s regulated retail customers over the remaining life of Bison through future renewable cost recovery rider fillings.