LONG-TERM DEBT - Components (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Long-term debt, components
Total debt	$ 3,324,478	$ 3,166,472
Less debt issuance costs	(26,810)	(27,412)
Less debt discounts	(9,846)	(9,906)
Plus debt premiums	15,385	15,752
Total debt adjusted for debt issuance costs, discounts and premiums	3,303,207	3,144,906
Less current maturities	(85,636)	(81,555)
Long-term debt	$ 3,217,571	$ 3,063,351

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.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt premium.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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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.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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