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Note 8 - Leases - Allocation of Lease Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Operating lease cost	$ 5,371
Variable lease cost	1,068
Total lease cost	6,439
Variable lease cost	1,068
Fixed Assets [Member]
Operating lease cost	29
Variable lease cost	0
Total lease cost	29
Variable lease cost	0
Production Fuel [Member]
Operating lease cost	952
Variable lease cost	0
Total lease cost	952
Variable lease cost	0
Cost of Sales [Member]
Operating lease cost	3,848
Variable lease cost	1,068
Total lease cost	4,916
Variable lease cost	1,068
Electric Operating and Maintenance Expenses [Member]
Operating lease cost	334
Variable lease cost	0
Total lease cost	334
Variable lease cost	0
Other Nonelectric Expenses [member]
Operating lease cost	208
Variable lease cost	0
Total lease cost	208
Variable lease cost	$ 0

X

- Definition

The sum of the right-of-use asset amortization, discount and variable lease costs.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

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X

- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971

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