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Financing: Schedule of Short-term Debt and Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Short-term Debt [Line Items]
Notes payable	$ 815,870	$ 234,040
Letters of Credit	16,629	24,730
Revolving Credit Facility
Short-term Debt [Line Items]
Notes payable	0	0
Letters of Credit	16,629	24,730
Term Loan
Short-term Debt [Line Items]
Notes payable	600,000	0
Letters of Credit	0	0
Commercial Paper
Short-term Debt [Line Items]
Notes payable	215,870	234,040
Letters of Credit	$ 0	$ 0

X

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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Period Type:	instant

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Period Type:	duration

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