EQUITY INVESTMENTS - Income From Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Representation of investee financial information in the summarized equity method investments (as a percent)	100.00%
INCOME STATEMENT DATA:
Revenue	$ 145,068	$ 126,684
Operating income	49,782	45,645
Net income	24,750	30,112
Net income attributable to investee	$ 22,959	$ 23,987

Equity Method Investment, Summarized Financial Information, Net Income (Loss) Attributable To Equity Method Investee

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- Definition

Represents the percentage of investee financial information in the summarized equity method investments.

+ References

No definition available.

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- Definition

Amount of income (loss) from continuing operations reported by an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721683-107760

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33912-111571

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The amount of net income (loss) reported by an equity method investment of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721683-107760

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-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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-Name Accounting Standards Codification
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- Definition

The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity.

+ References

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