RECENTLY ADOPTED ACCOUNTING PRONOUNCEMENTS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2019	Jan. 01, 2019	Jan. 01, 2018	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liability					$ 23,868
Operating lease right-of-use asset					23,286
Cumulative effect of new accounting principle in period of adoption		$ 741,557	$ 787,882	$ 933,562	279,816
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201609Member	us-gaap:AccountingStandardsUpdate201409	us-gaap:AccountingStandardsUpdate201409Member	us-gaap:AccountingStandardsUpdate201609Member
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liability					$ 23,900	$ 8,500
Operating lease right-of-use asset						$ 7,600
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption			$ 1,136	$ 21,558			$ 1,100	$ 21,600