SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets	$ 581,431	$ 631,572
Total intangible assets	$ 613,431	663,572
Software
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	3 years
Distribution Relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets	$ 377,441	402,975
Trade names
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets	78,629	85,340
Technology
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets	93,433	107,343
Other
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets	$ 31,928	35,914
Minimum | Distribution Relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	14 years
Minimum | Trade names
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	13 years
Minimum | Technology
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	7 years
Maximum | Distribution Relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	22 years
Maximum | Trade names
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	17 years
Maximum | Technology
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life	14 years
Insurance Licenses
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 32,000	$ 32,000