Fair value of all asset derivatives designated as cash flow hedging instruments.

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

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Amount of hedged item in hedging relationship. Excludes hedged asset or liability.

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The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

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Amount, after tax and reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

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DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Cash Flow Hedge) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net after-tax loss included in accumulated other comprehensive earnings	$ 393	$ (346)
Derivatives in Cash Flow Hedging Relationships
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	6,069	$ (5,681)
Cross Currency Swap Contract \| Derivatives in Cash Flow Hedging Relationships
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged			$ 280,000
Net after-tax loss included in accumulated other comprehensive earnings	2,000
Fair value of derivative asset	3,600
Cross Currency Swap Contract: Interest Component \| Derivatives in Cash Flow Hedging Relationships
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount expected to be recognized in earnings in next twelve months related to cross currency swap contract	$ 5,100
Notes payable to banks
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Proceeds from debt			$ 280,000
Interest rate on notes (as a percent)	1.36%		1.36%	1.36%