The Debt Service Ratio (DSR) requirement per the terms of long-term debt agreements.

No definition available.

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- Definition

The Equity to Capitalization Ratio (ECR) requirement per the terms of long-term debt agreements.

+ References

No definition available.

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- Definition

The number of unsecured debt instruments.

+ References

No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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.

+ Details

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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- References

No definition available.

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- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- References

No definition available.

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LONG-TERM DEBT - Other Information (Details) $ in Thousands	12 Months Ended
LONG-TERM DEBT - Other Information (Details) $ in Thousands	Dec. 31, 2019 USD ($) instrument	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt
Long-term debt	$ 3,063,351	$ 3,109,301
Unsecured debt
Number of unsecured debt instruments \| instrument	1
Unsecured notes	$ 27,100
Credit facility information
Outstanding borrowings	3,166,472	3,227,663
Proceeds from debt draw	$ 34,910	150,090	$ 60,000
Minimum
Credit facility information
Equity to capitalization ratio (ECR) requirement	18.00%
Debt service ratio (DSR) requirement	1.10
Springerville certificates, Series B, 7.14%, due through 2033
Credit facility information
Outstanding borrowings	$ 371,211	$ 405,000
Springerville certificates, Series B, 7.14%, due through 2033 \| Minimum
Credit facility information
Debt service ratio (DSR) requirement	1.02
2018 Revolving Credit Agreement
Credit facility information
Maximum borrowing capacity	$ 650,000
Available borrowing capacity	397,000
Outstanding borrowings	0
2018 Revolving Credit Agreement \| Commercial Paper
Credit facility information
Available borrowing capacity	$ 247,000