SEGMENT REPORTING - Reconciliation of Operating Income to Consolidated Income (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Adjustment for:
Amortization of intangible assets	$ 3,814	$ 4,358
Income from operations	14,816	11,149
Interest expense	5,040	5,041
Other income, net	(33)	(22)
Income before income taxes	9,809	6,130
Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Operating income for reportable segments	29,865	26,266
Segment Reconciling Items
Adjustment for:
Amortization of intangible assets	3,814	4,358
Corporate
Adjustment for:
Corporate expenses	$ 11,235	$ 10,759

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Operating income for reportable segments before amortization of intangibles, corporate and other expense, net.

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Amount of the cost of borrowed funds accounted for as interest expense.

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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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