BORROWINGS (Details 2) - USD ($)			1 Months Ended						3 Months Ended		6 Months Ended
	Dec. 16, 2015	May 07, 2015	Apr. 30, 2016	Mar. 31, 2016	Nov. 30, 2015	Jul. 31, 2015	Jun. 30, 2015	Feb. 28, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	May 31, 2016	Dec. 31, 2015
Details of Company's borrowings
Collateralized loan obligation secured debt repaid											$ 847,764,000	$ 743,048,000
Collateralized Loan Obligation Secured Notes
Details of Company's borrowings
Fair value, option, credit risk, gains (losses) on liabilities									$ 0	$ 0	0	0
CLO 2005-2 Senior Secured Notes
Details of Company's borrowings
Collateralized loan obligation secured debt repaid					$ 140,200,000
CLO 2005-1 secured notes
Details of Company's borrowings
Collateralized loan obligation secured debt repaid						$ 142,400,000
CLO 2006-1 senior secured notes
Details of Company's borrowings
Collateralized loan obligation secured debt repaid								$ 181,800,000
Contractual notional amount terminated								$ 84,000,000
CLO 2007-1 secured notes
Details of Company's borrowings
Collateralized loan obligation secured debt repaid									486,300,000		598,500,000
Par amount of notes issued									945,569,000		945,569,000			$ 1,544,032,000
Senior Notes Legacy CLO
Details of Company's borrowings
Collateralized loan obligation secured debt repaid										375,600,000		545,400,000
CLO 2011-1 senior debt
Details of Company's borrowings
Collateralized loan obligation secured debt repaid				$ 249,300,000						29,300,000		30,800,000
Par amount of notes issued														249,301,000
Subordinated Notes to Affiliate
Details of Company's borrowings
Par amount of notes issued													$ 96,500,000.0
CLO 2007-A subordinated notes
Details of Company's borrowings
Collateralized loan obligation secured debt repaid			$ 15,100,000
Par amount of notes issued														15,096,000
Notes C L O13
Details of Company's borrowings
Par amount of notes issued	$ 412,000,000
CLO 13 secured notes
Details of Company's borrowings
Par amount of notes issued									370,000,000		370,000,000			370,000,000
CLO 13 secured notes | Nonaffiliates
Details of Company's borrowings
Par amount of notes issued	370,000,000
Floating rate senior secured note	350,000,000
Fixed rate senior secured note	$ 20,000,000
Fixed rate (as a percent)	3.83%
CLO 13 secured notes | Nonaffiliates | LIBOR
Details of Company's borrowings
Percentage of margin added to reference rate to determine interest rate on debt (in percentage)	2.19%
CLO 2007-1 Class D and E secured notes
Details of Company's borrowings
Par amount of notes issued							$ 35,000,000			35,000,000		35,000,000
Proceeds from senior notes							35,100,000
CLO 2005-2 Class E Secured Notes
Details of Company's borrowings
Par amount of notes issued						15,000,000	15,000,000			$ 15,000,000		$ 15,000,000
Proceeds from senior notes						$ 15,100,000	$ 15,100,000
CLO 13 secured notes
Details of Company's borrowings
Par amount of notes issued									4,000,000		4,000,000			4,000,000
CLO 13 secured notes | Nonaffiliates
Details of Company's borrowings
Par amount of notes issued	$ 4,000,000
CLO 11 Notes
Details of Company's borrowings
Par amount of notes issued		$ 564,500,000
CLO 11 secured notes
Details of Company's borrowings
Par amount of notes issued									507,750,000		507,750,000			507,750,000
CLO 11 secured notes | Nonaffiliates
Details of Company's borrowings
Par amount of notes issued		$ 507,800,000
CLO 11 secured notes | Nonaffiliates | LIBOR
Details of Company's borrowings
Percentage of margin added to reference rate to determine interest rate on debt (in percentage)		2.06%
CLO 11 subordinated notes
Details of Company's borrowings
Par amount of notes issued									$ 28,250,000		$ 28,250,000			$ 28,250,000
CLO 11 subordinated notes | Nonaffiliates
Details of Company's borrowings
Par amount of notes issued		$ 28,300,000.0