XML 39 R27.htm IDEA: XBRL DOCUMENT
v3.20.2

Note 4 - Regulatory Assets and Liabilities (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2020
Notes Tables |
Schedule of Regulatory Assets and Liabilities [Table Text Block] |
|  | September 30, 2020 |  |  | Remaining Recovery/ |
(in thousands) |  | Current |  |  | Long-Term |  |  | Total |  |  |  | Refund Period (months) |
Regulatory Assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Prior Service Costs and Actuarial Losses on Pensions and Other Postretirement Benefits1 |  | $ | 9,018 |  |  | $ | 122,765 |  |  | $ | 131,783 |  |  | see below |
Minnesota Transmission Cost Recovery Rider Accrued Revenues2 |  |  | 3,676 |  |  |  | 6,126 |  |  |  | 9,802 |  |  |  | 27 |
Accumulated Asset Retirement Obligation (ARO) Accretion/Depreciation Adjustment1 |  |  | - |  |  |  | 8,481 |  |  |  | 8,481 |  |  | asset lives |
Conservation Improvement Program Costs and Incentives2 |  |  | 1,040 |  |  |  | 2,094 |  |  |  | 3,134 |  |  |  | 24 |
Nonservice Costs Components of Postretirement Benefits Capitalized for Ratemaking Purposes and Subject to Deferred Recovery1 |  |  | - |  |  |  | 2,149 |  |  |  | 2,149 |  |  | asset lives |
MISO Schedule 26/26A Transmission Cost Recovery Rider True-ups1 |  |  | 1,234 |  |  |  | 559 |  |  |  | 1,793 |  |  |  | 27 |
Unrecovered Project Costs – Minnesota1 |  |  | 401 |  |  |  | 1,092 |  |  |  | 1,493 |  |  |  | 21 |
Minnesota Renewable Resource Rider Accrued Revenues2 |  |  | 1,203 |  |  |  | - |  |  |  | 1,203 |  |  |  | 12 |
Unrecovered Project Costs – North Dakota1 |  |  | - |  |  |  | 856 |  |  |  | 856 |  |  |  | 21 |
Minnesota SPP Transmission Cost Recovery Tracker1 |  |  | - |  |  |  | 759 |  |  |  | 759 |  |  | see below |
Debt Reacquisition Premiums1 |  |  | 204 |  |  |  | 379 |  |  |  | 583 |  |  |  | 144 |
Unrecovered Project Costs – South Dakota1 |  |  | 144 |  |  |  | 357 |  |  |  | 501 |  |  |  | 24 |
South Dakota Deferred Rate Case Expenses Subject to Recovery1 |  |  | 137 |  |  |  | 143 |  |  |  | 280 |  |  |  | 25 |
North Dakota Deferred Rate Case Expenses Subject to Recovery1 |  |  | 122 |  |  |  | 152 |  |  |  | 274 |  |  |  | 27 |
Deferred Marked-to-Market Losses1 |  |  | 186 |  |  |  | - |  |  |  | 186 |  |  |  | 3 |
North Dakota Generation Cost Recovery Rider Accrued Revenue2 |  |  | 66 |  |  |  | - |  |  |  | 66 |  |  |  | 9 |
Deferred Lease Expenses1 |  |  | - |  |  |  | 65 |  |  |  | 65 |  |  |  | 56 |
Minnesota Environmental Cost Recovery Rider Accrued Revenues2 |  |  | 4 |  |  |  | - |  |  |  | 4 |  |  |  | 12 |
Total Regulatory Assets |  | $ | 17,435 |  |  | $ | 145,977 |  |  | $ | 163,412 |  |  |  |  |
Regulatory Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Income Taxes |  | $ | - |  |  | $ | 136,630 |  |  | $ | 136,630 |  |  | asset lives |
Accumulated Reserve for Estimated Removal Costs – Net of Salvage |  |  | - |  |  |  | 99,617 |  |  |  | 99,617 |  |  | asset lives |
Refundable Fuel Clause Adjustment Revenues |  |  | 9,208 |  |  |  | - |  |  |  | 9,208 |  |  |  | 12 |
North Dakota Transmission Cost Recovery Rider Accrued Refund |  |  | 1,233 |  |  |  | - |  |  |  | 1,233 |  |  |  | 3 |
South Dakota Phase-In Rate Plan Rider Accrued Refund |  |  | 1,090 |  |  |  | - |  |  |  | 1,090 |  |  |  | 11 |
Revenue for Rate Case Expenses Subject to Refund – Minnesota |  |  | - |  |  |  | 577 |  |  |  | 577 |  |  | see below |
Prior Service Costs and Actuarial Gains on Postretirement Benefits |  |  | 471 |  |  |  | - |  |  |  | 471 |  |  |  | 12 |
North Dakota Renewable Resource Recovery Rider Accrued Refund |  |  | 444 |  |  |  | - |  |  |  | 444 |  |  |  | 6 |
South Dakota Transmission Cost Recovery Rider Accrued Refund |  |  | 232 |  |  |  | - |  |  |  | 232 |  |  |  | 5 |
Minnesota Energy Intensive Trade Exposed Rider Accrued Refund |  |  | 186 |  |  |  | - |  |  |  | 186 |  |  |  | 12 |
Other |  |  | 6 |  |  |  | 68 |  |  |  | 74 |  |  |  | 159 |
Total Regulatory Liabilities |  | $ | 12,870 |  |  | $ | 236,892 |  |  | $ | 249,762 |  |  |  |  |
Net Regulatory Asset/(Liability) Position |  | $ | 4,565 |  |  | $ | (90,915 | ) |  | $ | (86,350 | ) |  |  |  |
|  | December 31, 2019 |  |  | Remaining Recovery/ |
(in thousands) |  | Current |  |  | Long-Term |  |  | Total |  |  | Refund Period (months) |
Regulatory Assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Prior Service Costs and Actuarial Losses on Pensions and Other Postretirement Benefits1 |  | $ | 9,090 |  |  | $ | 129,102 |  |  | $ | 138,192 |  |  | see below |
Minnesota Transmission Cost Recovery Rider Accrued Revenues2 |  |  | 4,208 |  |  |  | - |  |  |  | 4,208 |  |  |  | 12 |
Accumulated Asset Retirement Obligation (ARO) Accretion/Depreciation Adjustment1 |  |  | - |  |  |  | 7,772 |  |  |  | 7,772 |  |  | asset lives |
Conservation Improvement Program Costs and Incentives2 |  |  | 4,024 |  |  |  | 2,844 |  |  |  | 6,868 |  |  |  | 21 |
Nonservice Costs Components of Postretirement Benefits Capitalized for Ratemaking Purposes and Subject to Deferred Recovery1 |  |  | - |  |  |  | 1,681 |  |  |  | 1,681 |  |  | asset lives |
MISO Schedule 26/26A Transmission Cost Recovery Rider True-ups1 |  |  | 2,033 |  |  |  | 968 |  |  |  | 3,001 |  |  |  | 24 |
Unrecovered Project Costs – Minnesota1 |  |  | 715 |  |  |  | 225 |  |  |  | 940 |  |  |  | 16 |
Minnesota Renewable Resource Rider Accrued Revenues2 |  |  | 131 |  |  |  | - |  |  |  | 131 |  |  |  | 12 |
Minnesota SPP Transmission Cost Recovery Tracker1 |  |  | - |  |  |  | 202 |  |  |  | 202 |  |  | see below |
Debt Reacquisition Premiums1 |  |  | 201 |  |  |  | 548 |  |  |  | 749 |  |  |  | 153 |
Unrecovered Project Costs – South Dakota1 |  |  | 144 |  |  |  | 253 |  |  |  | 397 |  |  |  | 33 |
South Dakota Deferred Rate Case Expenses Subject to Recovery1 |  |  | 138 |  |  |  | 245 |  |  |  | 383 |  |  |  | 34 |
North Dakota Deferred Rate Case Expenses Subject to Recovery1 |  |  | 122 |  |  |  | 244 |  |  |  | 366 |  |  |  | 36 |
Deferred Marked-to-Market Losses1 |  |  | 743 |  |  |  | - |  |  |  | 743 |  |  |  | 12 |
Deferred Lease Expenses1 |  |  | - |  |  |  | 54 |  |  |  | 54 |  |  |  | 39 |
Minnesota Environmental Cost Recovery Rider Accrued Revenues2 |  |  | 4 |  |  |  | - |  |  |  | 4 |  |  |  | 12 |
South Dakota Transmission Cost Recovery Rider Accrued Revenues2 |  |  | 97 |  |  |  | - |  |  |  | 97 |  |  |  | 2 |
Total Regulatory Assets |  | $ | 21,650 |  |  | $ | 144,138 |  |  | $ | 165,788 |  |  |  |  |
Regulatory Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Income Taxes |  | $ | - |  |  | $ | 141,707 |  |  | $ | 141,707 |  |  | asset lives |
Accumulated Reserve for Estimated Removal Costs – Net of Salvage |  |  | - |  |  |  | 97,726 |  |  |  | 97,726 |  |  | asset lives |
Refundable Fuel Clause Adjustment Revenues |  |  | 3,982 |  |  |  | - |  |  |  | 3,982 |  |  |  | 12 |
North Dakota Transmission Cost Recovery Rider Accrued Refund |  |  | 700 |  |  |  | - |  |  |  | 700 |  |  |  | 12 |
South Dakota Phase-In Rate Plan Rider Accrued Refund |  |  | 355 |  |  |  | - |  |  |  | 355 |  |  |  | 9 |
Revenue for Rate Case Expenses Subject to Refund – Minnesota |  |  | - |  |  |  | 401 |  |  |  | 401 |  |  | see below |
Prior Service Costs and Actuarial Gains on Postretirement Benefits |  |  | 471 |  |  |  | - |  |  |  | 471 |  |  |  | 12 |
North Dakota Renewable Resource Recovery Rider Accrued Refund |  |  | 1,515 |  |  |  | - |  |  |  | 1,515 |  |  |  | 12 |
Minnesota Energy Intensive Trade Exposed Rider Accrued Refund |  |  | 164 |  |  |  | - |  |  |  | 164 |  |  |  | 12 |
North Dakota Generation Cost Recovery Rider Accrued Refund |  |  | 287 |  |  |  | - |  |  |  | 287 |  |  |  | 6 |
Other |  |  | 6 |  |  |  | 72 |  |  |  | 78 |  |  |  | 168 |
Total Regulatory Liabilities |  | $ | 7,480 |  |  | $ | 239,906 |  |  | $ | 247,386 |  |  |  |  |
Net Regulatory Asset/(Liability) Position |  | $ | 14,170 |  |  | $ | (95,768 | ) |  | $ | (81,598 | ) |  |  |  |

X
- Definition Schedule of Regulatory Assets and Liabilities + References No definition available. + Details
Name: | ottr_ScheduleOfRegulatoryAssetsAndLiabilitiesTableTextBlock
Namespace Prefix: | ottr_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_TableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration