SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended	3 Months Ended
	Mar. 31, 2014	Sep. 30, 2013	Sep. 30, 2013	Mar. 31, 2015	Dec. 31, 2014
Segment Reporting Information
Total assets				$ 8,727,164	$ 8,951,625
Predecessor Company
Segment Reporting Information
Total revenues	140,590
Total investment costs and expenses	73,770
Total other income (loss)	72,840
Total other expenses	31,458
Income tax expense (benefit)	19
Net income (loss)	108,183
Net income (loss) attributable to noncontrolling interests	0
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries	108,183	39,886	224,354
Predecessor Company | Reportable Segments | Credit
Segment Reporting Information
Total revenues	96,562
Total investment costs and expenses	45,873
Total other income (loss)	64,516
Total other expenses	15,835
Income tax expense (benefit)	19
Net income (loss)	99,351
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries		33,795	247,954
Predecessor Company | Reportable Segments | Natural Resources
Segment Reporting Information
Total revenues	44,028
Total investment costs and expenses	27,576
Total other income (loss)	(5,389)
Total other expenses	1,154
Net income (loss)	9,909
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries		5,354	18,147
Predecessor Company | Reportable Segments | Other
Segment Reporting Information
Total revenues	0
Total investment costs and expenses	321
Total other income (loss)	13,713
Total other expenses	140
Income tax expense (benefit)	0
Net income (loss)	13,252
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries		2,344	6,359
Predecessor Company | Reconciling Items
Segment Reporting Information
Total other expenses	14,329
Net income (loss)	(14,329)
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries		(1,607)	(48,106)
Incentive fees	12,900
Successor Company
Segment Reporting Information
Total revenues				97,786
Total investment costs and expenses				57,653
Total other income (loss)				(69,164)
Total other expenses				17,168
Income tax expense (benefit)				347
Net income (loss)				(46,546)
Net income (loss) attributable to noncontrolling interests				(6,071)
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries				(40,475)
Successor Company | Reportable Segments | Credit
Segment Reporting Information
Total revenues				94,958
Total investment costs and expenses				55,967
Total other income (loss)				(65,992)
Total other expenses				16,403
Income tax expense (benefit)				48
Net income (loss)				(43,452)
Net income (loss) attributable to noncontrolling interests				(5,858)
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries				(37,594)
Total assets				8,202,142	8,438,227
Successor Company | Reportable Segments | Natural Resources
Segment Reporting Information
Total revenues				2,828
Total investment costs and expenses				1,340
Total other income (loss)				(7,753)
Total other expenses				510
Income tax expense (benefit)				0
Net income (loss)				(6,775)
Net income (loss) attributable to noncontrolling interests				(213)
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries				(6,562)
Total assets				297,169	300,281
Successor Company | Reportable Segments | Other
Segment Reporting Information
Total revenues				0
Total investment costs and expenses				346
Total other income (loss)				4,581
Total other expenses				155
Income tax expense (benefit)				299
Net income (loss)				3,781
Net income (loss) attributable to noncontrolling interests				0
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries				3,781
Total assets				227,853	213,006
Successor Company | Reconciling Items
Segment Reporting Information
Total other expenses				100
Income tax expense (benefit)				0
Net income (loss)				(100)
Net income (loss) attributable to noncontrolling interests				0
Net income (loss) attributable to KKR Financial Holdings LLC and Subsidiaries				(100)
Total assets				0	111
Noncontrolling interests | Successor Company
Segment Reporting Information
Net income (loss)				(6,071)
Total assets				96,200	100,200
Noncontrolling interests | Successor Company | Credit
Segment Reporting Information
Total assets				56,800	62,700
Noncontrolling interests | Successor Company | Natural Resources
Segment Reporting Information
Total assets				$ 39,400	$ 37,400