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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Face (par) amount of debt instrument at time of issuance.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

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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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LONG-TERM DEBT - Debt Maturities and Debt Issuance Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 07, 2017	Jul. 10, 2017	Feb. 16, 2017
Debt maturities
Thereafter		$ 625,005
Total		625,005
Debt Issuance Costs
Costs associated with the issuance of debt capitalized	$ 4,334	17,799
6.75% senior notes due 2025
Debt maturities
Aggregate principal amount drawn	625,005	425,005	$ 850,000	$ 850,000	$ 850,000
Senior revolving credit facility and additional 2025 notes
Debt Issuance Costs
Costs associated with the issuance of debt capitalized	4,200
Senior revolving credit facility
Debt Issuance Costs
Unamortized debt issuance costs	$ 11,100	$ 8,300