SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 30, 2017	Dec. 31, 2016
Collateralized Debt Obligation disclosures
Assets	$ 6,006,936		$ 5,851,057
Liabilities	4,059,911		3,982,872
Total borrowings	$ 3,882,021		3,626,191
Minimum percentage of voting interest required to consolidate non-VIEs	50.00%
Collateralized Debt Obligation (CLOs) VIEs
Collateralized Debt Obligation disclosures
Corporate debt investment, par amount	$ 3,100,000		3,100,000
Estimated fair value of corporate debt investments	3,100,000		3,100,000
Total borrowings	$ 3,100,000		3,200,000
Cumulative-Effect Adjustment, Deconsolidation of Variable Interest Entity
Collateralized Debt Obligation disclosures
Assets		$ (760,000)	(1,000,000)
Liabilities		$ (760,000)	$ (1,000,000)