Amount of amortization expense attributable to debt issuance costs.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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 effective interest rate at the end of the reporting period.

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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.

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

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REVOLVING LOAN (Details) - USD ($)		3 Months Ended	12 Months Ended
REVOLVING LOAN (Details) - USD ($)	Jun. 27, 2018	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	May 07, 2014
Debt Instrument [Line Items]
Senior secured credit agreement term	5 years
Revolver loan - long-term			$ 156,000,000	$ 0
Capitalized costs net of accumulated amortization			1,268,000	536,000
Amortization expense pertaining to capitalized costs			$ 680,000	$ 474,000	$ 526,000
Write off of deferred financing costs		$ 363,000
Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 500,000,000
Interest rate			3.647%
Commitment fee percentage			0.175%
Unused portion of revolving loan			$ 344,000,000
Credit Agreement \| Minimum
Debt Instrument [Line Items]
Commitment fee percentage			0.15%
Credit Agreement \| Maximum
Debt Instrument [Line Items]
Commitment fee percentage			0.275%
Term A Loan
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 350,000,000
Payments for outstanding balance			$ 210,750,000
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 100,000,000
Installment payments required			$ 0