0001001 - Document - Cover Page link:presentationLink link:calculationLink link:definitionLink 1001002 - Statement - Condensed Consolidated Statements of Income (unaudited) link:presentationLink link:calculationLink link:definitionLink 1002003 - Statement - Condensed Consolidated Statements of Comprehensive Income (unaudited) link:presentationLink link:calculationLink link:definitionLink 1003004 - Statement - Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 1004005 - Statement - Condensed Consolidated Balance Sheets (unaudited) link:presentationLink link:calculationLink link:definitionLink 1005006 - Statement - Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 1006007 - Statement - Condensed Consolidated Statements of Cash Flows (unaudited) link:presentationLink link:calculationLink link:definitionLink 1007008 - Statement - Condensed Consolidated Statements of Equity (unaudited) link:presentationLink link:calculationLink link:definitionLink 1008009 - Statement - Condensed Consolidated Statements of Equity (unaudited) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 2101101 - Disclosure - Management's Statement: link:presentationLink link:calculationLink link:definitionLink 2202201 - Disclosure - Management's Statement (Policies) link:presentationLink link:calculationLink link:definitionLink 2103102 - Disclosure - Regulatory Matters: link:presentationLink link:calculationLink link:definitionLink 2304301 - Disclosure - Regulatory Matters (Tables) link:presentationLink link:calculationLink link:definitionLink 2405401 - Disclosure - Regulatory Matters (Details) link:presentationLink link:calculationLink link:definitionLink 2406402 - Disclosure - Regulatory Matters: Winter Storm Uri (Details) link:presentationLink link:calculationLink link:definitionLink 2407403 - Disclosure - Regulatory Matters: Rate Review (Details) link:presentationLink link:calculationLink link:definitionLink 2108103 - Disclosure - Commitments, Contingencies and Guarantees: link:presentationLink link:calculationLink link:definitionLink 2409404 - Disclosure - Commitments, Contingencies and Guarantees (Details) link:presentationLink link:calculationLink link:definitionLink 2110104 - Disclosure - Revenue: link:presentationLink link:calculationLink link:definitionLink 2311302 - Disclosure - Revenue (Tables) link:presentationLink link:calculationLink link:definitionLink 2412405 - Disclosure - Disaggregation of Revenue (Details) link:presentationLink link:calculationLink link:definitionLink 2113105 - Disclosure - Financing: link:presentationLink link:calculationLink link:definitionLink 2314303 - Disclosure - Financing (Tables) link:presentationLink link:calculationLink link:definitionLink 2415406 - Disclosure - Financing: Schedule of Short-term Debt and Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 2416407 - Disclosure - Financing: Term Loan (Details) link:presentationLink link:calculationLink link:definitionLink 2417408 - Disclosure - Financing: Revolving Credit Facility and CP Program (Details) link:presentationLink link:calculationLink link:definitionLink 2418409 - Disclosure - Financing: Debt Covenants (Details) link:presentationLink link:calculationLink link:definitionLink 2119106 - Disclosure - Earnings Per Share: link:presentationLink link:calculationLink link:definitionLink 2320304 - Disclosure - Earnings Per Share (Tables) link:presentationLink link:calculationLink link:definitionLink 2421410 - Disclosure - Earnings Per Share: Earnings Per Share Reconciliation (Details) link:presentationLink link:calculationLink link:definitionLink 2422411 - Disclosure - Earnings Per Share: Anti-dilutive shares (Details) link:presentationLink link:calculationLink link:definitionLink 2123107 - Disclosure - Risk Management and Derivatives: link:presentationLink link:calculationLink link:definitionLink 2324305 - Disclosure - Risk Management and Derivatives (Tables) link:presentationLink link:calculationLink link:definitionLink 2425412 - Disclosure - Risk Management and Derivatives: Utilities (Details) link:presentationLink link:calculationLink link:definitionLink 2426413 - Disclosure - Risk Management and Derivatives: Derivatives by Balance Sheet Classification (Details) link:presentationLink link:calculationLink link:definitionLink 2427414 - Disclosure - Risk Management and Derivatives: Derivatives Designated as Hedge Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 2428415 - Disclosure - Risk Management and Derivatives: Derivatives Not Designated as Hedge Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 2129108 - Disclosure - Fair Value Measurements: link:presentationLink link:calculationLink link:definitionLink 2330306 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 2431416 - Disclosure - Fair Value Measurements: Schedule of Fair Values (Details) link:presentationLink link:calculationLink link:definitionLink 2432417 - Disclosure - Fair Value Measurements: Other Fair Value Measurements (Details) link:presentationLink link:calculationLink link:definitionLink 2133109 - Disclosure - Other Comprehensive Income: link:presentationLink link:calculationLink link:definitionLink 2334307 - Disclosure - Other Comprehensive Income (Tables) link:presentationLink link:calculationLink link:definitionLink 2435418 - Disclosure - Other Comprehensive Income: Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details) link:presentationLink link:calculationLink link:definitionLink 2436419 - Disclosure - Other Comprehensive Income (Loss): Accumulated Other Comprehensive Income (Details) link:presentationLink link:calculationLink link:definitionLink 2137110 - Disclosure - Employee Benefit Plans: link:presentationLink link:calculationLink link:definitionLink 2338308 - Disclosure - Employee Benefit Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 2439420 - Disclosure - Employee Benefit Plans (Details) link:presentationLink link:calculationLink link:definitionLink 2140111 - Disclosure - Income Taxes: link:presentationLink link:calculationLink link:definitionLink 2441421 - Disclosure - Income Taxes: Winter Storm Uri (Details) link:presentationLink link:calculationLink link:definitionLink 2442422 - Disclosure - Income Taxes (Details) link:presentationLink link:calculationLink link:definitionLink 2143112 - Disclosure - Business Segment Information: link:presentationLink link:calculationLink link:definitionLink 2344309 - Disclosure - Business Segment Information (Tables) link:presentationLink link:calculationLink link:definitionLink 2445423 - Disclosure - Business Segment Information: Segment and Corporate Assets (Details) link:presentationLink link:calculationLink link:definitionLink 2446424 - Disclosure - Business Segment Information: Information Relating to Segment Statement of Income (Details) link:presentationLink link:calculationLink link:definitionLink 2147113 - Disclosure - Selected Balance Sheet Information: link:presentationLink link:calculationLink link:definitionLink 2348310 - Disclosure - Selected Balance Sheet Information (Tables) link:presentationLink link:calculationLink link:definitionLink 2449425 - Disclosure - Selected Balance Sheet Information: Accounts Receivable (Details) link:presentationLink link:calculationLink link:definitionLink 2450426 - Disclosure - Selected Balance Sheet Information: Changes to Allowance for Credit Losses (Details) link:presentationLink link:calculationLink link:definitionLink 2451427 - Disclosure - Selected Balance Sheet Information: Materials and Supplies (Details) link:presentationLink link:calculationLink link:definitionLink 2452428 - Disclosure - Selected Balance Sheet Information: Accrued Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink