Amount of amortization expense attributable to debt issuance costs.

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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.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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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 Issuance Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Debt issuance costs	$ 28,200
Debt issuance costs	26,115		$ 27,101
Amortization of debt issuance costs	1,110	$ 1,945
ABL Facility
Debt Instrument [Line Items]
Debt issuance costs	2,000
Debt issuance costs	0		$ 0
ABL Facility \| Other current assets
Debt Instrument [Line Items]
Debt issuance costs	$ 1,200