Amount of Interest Costs Reduction as a result of Debt Redemption

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Debt Instrument, Issue Price Percentage

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Percentage of Notes Registered under the Securities Act of 1933

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Restrictive Covenants Exception for Dividend or Distribution Amount during fiscal year

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Restrictive Covenants Exception for total Dividend Payment and other Restricted Payments

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Total Debt Redemption Costs on 25% Note Redemption

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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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Contractual interest rate for funds borrowed, under the debt agreement.

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Date the debt instrument was issued, in CCYY-MM-DD format.

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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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Percentage of principal amount of debt redeemed.

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

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Gross amount of debt extinguished.

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Aggregate amount of interest paid or due on all long-term debt.

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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 of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Long-Term Debt - Additional Information (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Aug. 25, 2019	Jun. 23, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Sep. 19, 2017
Debt Instrument [Line Items]
Annual Interest Costs Reduction as a result of Debt Redemption	$ 3,800
Payment for Debt Extinguishment or Debt Prepayment Cost	1,700				$ 1,688	$ 0
Write off of Deferred Debt Issuance Cost			$ 200		184	0
Long-term Debt, Gross			150,000		150,000		$ 200,000
Debt Instrument, Increase, Accrued Interest			1,900
Long-term debt			149,467		149,467		$ 199,096
Repayments of Secured Debt	$ 50,000				50,000	0
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed	25.00%
6.75% Senior Secured Notes [Member] \| Senior Secured Notes
Debt Instrument [Line Items]
Private placement date		Jun. 23, 2017
Debt Instrument, Face Amount		$ 200,000
Interest rate		6.75%
Debt Issuance Costs, Gross		$ 4,300
Interest expense on note			3,000	$ 3,400	9,800	$ 10,100
Debt Instrument, Issue Price Percentage		100.00%
Percentage of Notes Registered under the Securities Act of 1933								99.80%
8.75% Senior Secured Notes [Member] \| Senior Secured Notes
Debt Instrument [Line Items]
Interest rate		8.75%
Extinguishment of Debt, Amount		$ 120,000
Oppenheimer [Member] \| 6.75% Senior Secured Notes [Member] \| Senior Secured Notes
Debt Instrument [Line Items]
Debt Issuance Costs, Gross		3,000
Third Party [Member] \| 6.75% Senior Secured Notes [Member] \| Senior Secured Notes
Debt Instrument [Line Items]
Debt Issuance Costs, Gross		$ 1,300
Maximum [Member] \| 6.75% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Restrictive Covenants Exception for Dividend or Distribution Amount during fiscal year					20,000
Restrictive Covenants Exception for total Dividend Payment and other Restricted Payments			$ 10,000		$ 10,000