SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Apr. 30, 2014	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting Information
Total assets	$ 7,899,443				$ 7,899,443	$ 8,951,625
Predecessor Company
Segment Reporting Information
Total revenues			$ 217,242
Total investment costs and expenses			101,825
Total other income (loss)			56,334
Total other expenses			65,609
Income tax expense (benefit)			162
Net income (loss)			105,980
Net income (loss) attributable to noncontrolling interests			0
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries			105,980
Total CLO management fees			29,841
Predecessor Company | Reportable Segments | Credit
Segment Reporting Information
Total revenues			134,255
Total investment costs and expenses			62,485
Total other income (loss)			76,046
Total other expenses			23,121
Income tax expense (benefit)			146
Net income (loss)			124,549
Predecessor Company | Reportable Segments | Natural Resources
Segment Reporting Information
Total revenues			61,782
Total investment costs and expenses			38,915
Total other income (loss)			(8,123)
Total other expenses			1,633
Income tax expense (benefit)			0
Net income (loss)			13,111
Predecessor Company | Reportable Segments | Other
Segment Reporting Information
Total revenues			21,205
Total investment costs and expenses			425
Total other income (loss)			(11,589)
Total other expenses			230
Income tax expense (benefit)			16
Net income (loss)			8,945
Predecessor Company | Reconciling Items
Segment Reporting Information
Total revenues			0
Total investment costs and expenses			0
Total other income (loss)			0
Total other expenses			40,625
Income tax expense (benefit)			0
Net income (loss)			(40,625)
Total CLO management fees			12,900
Successor Company
Segment Reporting Information
Total revenues	89,109	$ 124,756		$ 219,069	292,586
Total investment costs and expenses	50,352	61,340		117,004	170,455
Total other income (loss)	(185,449)	(125,685)		(104,798)	(246,578)
Total other expenses	11,547	14,898		29,262	40,984
Income tax expense (benefit)	94	34		62	1,170
Net income (loss)	(158,333)	(77,201)		(32,057)	(166,601)
Net income (loss) attributable to noncontrolling interests	(6,676)	816		816	(15,452)
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries	(151,657)	(78,017)		(32,873)	(151,149)
Total CLO management fees	9,449	12,544		22,950	29,486
Successor Company | Reportable Segments | Credit
Segment Reporting Information
Total revenues	79,698	98,413		160,724	265,176
Total investment costs and expenses	47,948	46,412		81,822	163,246
Total other income (loss)	(149,952)	(132,098)		(114,985)	(216,786)
Total other expenses	11,285	14,136		26,889	39,702
Income tax expense (benefit)	64	34		58	126
Net income (loss)	(129,551)	(94,267)		(63,030)	(154,684)
Net income (loss) attributable to noncontrolling interests	(2,727)	816		816	(8,403)
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries	(126,824)	(95,083)		(63,846)	(146,281)
Total assets	7,412,244				7,412,244	8,438,227
Successor Company | Reportable Segments | Natural Resources
Segment Reporting Information
Total revenues	3,876	17,929		49,859	13,055
Total investment costs and expenses	2,016	14,617		34,674	6,062
Total other income (loss)	(36,236)	(1,514)		(6,394)	(50,337)
Total other expenses	114	617		2,010	800
Income tax expense (benefit)	0	0		0	0
Net income (loss)	(34,490)	1,181		6,781	(44,144)
Net income (loss) attributable to noncontrolling interests	(3,949)	0		0	(7,049)
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries	(30,541)	1,181		6,781	(37,095)
Total assets	252,618				252,618	300,281
Successor Company | Reportable Segments | Other
Segment Reporting Information
Total revenues	5,535	8,414		8,486	14,355
Total investment costs and expenses	388	311		508	1,147
Total other income (loss)	739	7,927		16,581	20,545
Total other expenses	99	145		328	333
Income tax expense (benefit)	30	0		4	1,044
Net income (loss)	5,757	15,885		24,227	32,376
Net income (loss) attributable to noncontrolling interests	0	0		0	0
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries	5,757	15,885		24,227	32,376
Total assets	234,581				234,581	213,006
Successor Company | Reconciling Items
Segment Reporting Information
Total revenues	0	0		0	0
Total investment costs and expenses	0	0		0	0
Total other income (loss)	0	0		0	0
Total other expenses	49	0		35	149
Income tax expense (benefit)	0	0		0	0
Net income (loss)	(49)	0		(35)	(149)
Net income (loss) attributable to noncontrolling interests	0	0		0	0
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries	(49)	$ 0		(35)	(149)
Total assets	0				0	111
Noncontrolling interests | Successor Company
Segment Reporting Information
Net income (loss)				$ 816	(15,452)
Total assets	86,000				86,000	100,200
Noncontrolling interests | Successor Company | Reportable Segments | Credit
Segment Reporting Information
Total assets	53,100				53,100	62,700
Noncontrolling interests | Successor Company | Reportable Segments | Natural Resources
Segment Reporting Information
Total assets	$ 32,900				$ 32,900	$ 37,400
Merger Transaction Costs | Predecessor Company | Reconciling Items
Segment Reporting Information
Total CLO management fees			$ 22,700