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Notes Payable, Current Maturities and Debt: Debt Offering (Details) - USD ($) $ in Thousands |  | 9 Months Ended
--- | --- | ---
Jun. 17, 2020 | Sep. 30, 2020 | Sep. 30, 2019
Debt Instrument [Line Items] |  |  |
Long-term debt - issuances |  | $ 400,000 | $ 400,000
Senior Unsecured Notes Due 2030 |  |  |
Debt Instrument [Line Items] |  |  |
Long-term debt - issuances | $ 400,000 |  |
Debt Instrument, Interest Rate, Stated Percentage | 2.50% |  |
Long-term Debt, Term | 10 years |  |

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- Definition Period between issuance and maturity of long-term debt, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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