ORGANIZATION - Summary of Total Consideration (Details) - Shellpoint Acquisition - USD ($)			12 Months Ended
	Dec. 31, 2018	Jul. 03, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Combination, Separately Recognized Transactions [Line Items]
Cash consideration		$ 212,300,000
Earnout Payment	$ 40,800,000	39,300,000	$ 39,300,000	$ 0	$ 0
Effective Settlement of Preexisting Relationships		173,900,000
Total consideration		425,500,000
Contingent consideration, high		$ 60,000,000
Contingent consideration, payment term		3 years
Contingent consideration, earnout payments fair value		$ 39,300,000
Minimum
Business Combination, Separately Recognized Transactions [Line Items]
Contingent consideration, low		0
Maximum
Business Combination, Separately Recognized Transactions [Line Items]
Contingent consideration, high		$ 60,000,000