BUSINESS COMBINATIONS - Narrative (Details) - USD ($) $ in Thousands			3 Months Ended						12 Months Ended
	Oct. 02, 2017	Apr. 01, 2017	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 06, 2017
Business Acquisition [Line Items]
Transaction and reorganization expenses			$ 19,000	$ 16,000	$ 19,000	$ 13,000	$ 21,000	$ 6,000
Goodwill			$ 102,003				$ 102,003		$ 102,003	$ 102,003
Bargain purchase gain									0	15,044	$ 0
Novae
Business Acquisition [Line Items]
Interests acquired	100.00%
Total purchase price paid	$ 616,926
Transaction and reorganization expenses									$ 26,000	$ 27,000
Goodwill	54,047
Finite lived other intangible assets	385,000
Value of business acquired - definite lived intangible asset	256,942
Indefinite lived intangible assets	94,748
Total liabilities assumed	3,342,912
Novae | Distribution networks
Business Acquisition [Line Items]
Finite lived other intangible assets	$ 128,463
Aviabel
Business Acquisition [Line Items]
Interests acquired		100.00%
Assets		$ 182,000
Total liabilities assumed		79,000
Bargain purchase gain		$ 15,000
Contessa Limited
Business Acquisition [Line Items]
Interests acquired												100.00%
Goodwill												$ 1,000