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

Note 4 - Regulatory Assets and Liabilities (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2020
Notes Tables |
Schedule of Regulatory Assets and Liabilities [Table Text Block] |
|  | June 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 |  |  | $ | 124,901 |  |  | $ | 133,919 |  |  | see below |
Accumulated Asset Retirement Obligation (ARO) Accretion/Depreciation Adjustment1 |  |  | - |  |  |  | 8,243 |  |  |  | 8,243 |  |  | asset lives |
Minnesota Transmission Cost Recovery Rider Accrued Revenues2 |  |  | 6,563 |  |  |  | - |  |  |  | 6,563 |  |  | 12 |
Conservation Improvement Program Costs and Incentives2 |  |  | 276 |  |  |  | 3,553 |  |  |  | 3,829 |  |  | 27 |
MISO Schedule 26/26A Transmission Cost Recovery Rider True-ups1 |  |  | 1,500 |  |  |  | 963 |  |  |  | 2,463 |  |  | 30 |
Nonservice Costs Components of Postretirement Benefits Capitalized for Ratemaking Purposes and Subject to Deferred Recovery1 |  |  | - |  |  |  | 1,974 |  |  |  | 1,974 |  |  | asset lives |
Minnesota Renewable Resource Rider Accrued Revenues2 |  |  | 722 |  |  |  | - |  |  |  | 722 |  |  | 12 |
Debt Reacquisition Premiums1 |  |  | 204 |  |  |  | 430 |  |  |  | 634 |  |  | 147 |
Big Stone II Unrecovered Project Costs – Minnesota1 |  |  | 583 |  |  |  | - |  |  |  | 583 |  |  | 10 |
Minnesota SPP Transmission Cost Recovery Tracker1 |  |  | - |  |  |  | 401 |  |  |  | 401 |  |  | see below |
Deferred Marked-to-Market Losses1 |  |  | 372 |  |  |  | - |  |  |  | 372 |  |  | 6 |
Big Stone II Unrecovered Project Costs – South Dakota1 |  |  | 144 |  |  |  | 180 |  |  |  | 324 |  |  | 27 |
South Dakota Deferred Rate Case Expenses Subject to Recovery1 |  |  | 138 |  |  |  | 177 |  |  |  | 315 |  |  | 28 |
North Dakota Generation Cost Recovery Rider Accrued Revenue2 |  |  | 312 |  |  |  | - |  |  |  | 312 |  |  | 12 |
North Dakota Deferred Rate Case Expenses Subject to Recovery1 |  |  | 122 |  |  |  | 183 |  |  |  | 305 |  |  | 30 |
Deferred Lease Expenses1 |  |  | - |  |  |  | 58 |  |  |  | 58 |  |  | 33 |
Minnesota Environmental Cost Recovery Rider Accrued Revenues2 |  |  | 4 |  |  |  | - |  |  |  | 4 |  |  | 12 |
Total Regulatory Assets |  | $ | 19,958 |  |  | $ | 141,063 |  |  | $ | 161,021 |  |  |  |
Regulatory Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Income Taxes |  | $ | - |  |  | $ | 138,517 |  |  | $ | 138,517 |  |  | asset lives |
Accumulated Reserve for Estimated Removal Costs – Net of Salvage |  |  | - |  |  |  | 99,055 |  |  |  | 99,055 |  |  | asset lives |
Refundable Fuel Clause Adjustment Revenues |  |  | 10,241 |  |  |  | - |  |  |  | 10,241 |  |  | 12 |
North Dakota Transmission Cost Recovery Rider Accrued Refund |  |  | 1,010 |  |  |  | - |  |  |  | 1,010 |  |  | 6 |
South Dakota Phase-In Rate Plan Rider Accrued Refund |  |  | 783 |  |  |  | - |  |  |  | 783 |  |  | 2 |
Revenue for Rate Case Expenses Subject to Refund – Minnesota |  |  | - |  |  |  | 518 |  |  |  | 518 |  |  | see below |
Prior Service Costs and Actuarial Gains on Postretirement Benefits |  |  | 471 |  |  |  | - |  |  |  | 471 |  |  | 12 |
Minnesota Energy Intensive Trade Exposed Rider Accrued Refund |  |  | 198 |  |  |  | - |  |  |  | 198 |  |  | 3 |
South Dakota Transmission Cost Recovery Rider Accrued Refund |  |  | 159 |  |  |  | - |  |  |  | 159 |  |  | 8 |
North Dakota Renewable Resource Recovery Rider Accrued Refund |  |  | 156 |  |  |  | - |  |  |  | 156 |  |  | 9 |
Other |  |  | 5 |  |  |  | 70 |  |  |  | 75 |  |  | 162 |
Total Regulatory Liabilities |  | $ | 13,023 |  |  | $ | 238,160 |  |  | $ | 251,183 |  |  |  |
Net Regulatory Asset/(Liability) Position |  | $ | 6,935 |  |  | $ | (97,097 | ) |  | $ | (90,162 | ) |  |  |
|  | December 31, 2019 |  |  |  |
(in thousands) |  | Current |  |  | Long-Term |  |  | Total |  |  | Remaining Recovery/ 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 |
Accumulated Asset Retirement Obligation (ARO) Accretion/Depreciation Adjustment1 |  |  | - |  |  |  | 7,772 |  |  |  | 7,772 |  |  | asset lives |
Minnesota Transmission Cost Recovery Rider Accrued Revenues2 |  |  | 4,208 |  |  |  | - |  |  |  | 4,208 |  |  | 12 |
Conservation Improvement Program Costs and Incentives2 |  |  | 4,024 |  |  |  | 2,844 |  |  |  | 6,868 |  |  | 21 |
MISO Schedule 26/26A Transmission Cost Recovery Rider True-ups1 |  |  | 2,033 |  |  |  | 968 |  |  |  | 3,001 |  |  | 24 |
Nonservice Costs Components of Postretirement Benefits Capitalized for Ratemaking Purposes and Subject to Deferred Recovery1 |  |  | - |  |  |  | 1,681 |  |  |  | 1,681 |  |  | asset lives |
Minnesota Renewable Resource Rider Accrued Revenues2 |  |  | 131 |  |  |  | - |  |  |  | 131 |  |  | 12 |
Debt Reacquisition Premiums1 |  |  | 201 |  |  |  | 548 |  |  |  | 749 |  |  | 153 |
Big Stone II Unrecovered Project Costs – Minnesota1 |  |  | 715 |  |  |  | 225 |  |  |  | 940 |  |  | 16 |
Minnesota SPP Transmission Cost Recovery Tracker1 |  |  | - |  |  |  | 202 |  |  |  | 202 |  |  | see below |
Deferred Marked-to-Market Losses1 |  |  | 743 |  |  |  | - |  |  |  | 743 |  |  | 12 |
Big Stone II 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 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 |
Minnesota Energy Intensive Trade Exposed Rider Accrued Refund |  |  | 164 |  |  |  | - |  |  |  | 164 |  |  | 12 |
North Dakota Renewable Resource Recovery Rider Accrued Refund |  |  | 1,515 |  |  |  | - |  |  |  | 1,515 |  |  | 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