Amount of amortization expense attributable to debt issuance costs.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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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 of the required periodic payments of both interest and principal.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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The carrying value as of the balance sheet date of the noncurrent portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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REVOLVING LOAN (Details) - USD ($)		3 Months Ended
REVOLVING LOAN (Details) - USD ($)	Jun. 27, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	May 07, 2014
Line of Credit Facility [Abstract]
Outstanding balance		$ 140,000,000		$ 156,000,000
Capitalized costs net of accumulated amortization		1,197,000		$ 1,268,000
Amortization expense pertaining to capitalized costs		$ 71,000	$ 109,000
Credit Agreement
Line of Credit Facility [Abstract]
Senior secured credit agreement term	5 years
Maximum borrowing capacity	$ 500,000,000
Interest rate		3.496%
Commitment fee percentage		0.15%
Unused portion of revolving loan		$ 360,000,000
Credit Agreement \| Minimum
Line of Credit Facility [Abstract]
Commitment fee percentage	0.15%
Credit Agreement \| Maximum
Line of Credit Facility [Abstract]
Commitment fee percentage	0.275%
Term Loan A
Line of Credit Facility [Abstract]
Maximum borrowing capacity					$ 350,000,000
Payments for outstanding balance	$ 210,750,000
Revolving Credit Facility
Line of Credit Facility [Abstract]
Maximum borrowing capacity					$ 100,000,000
Installment payments required		$ 0