SUMMARY OF QUARTERLY INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended							4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2014	Jun. 30, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Mar. 31, 2014	Apr. 30, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2013
Successor Company
Entity Information [Line Items]
Total revenues		$ 94,313	$ 82,670	$ 89,109	$ 105,691	$ 97,786	$ 131,276	$ 124,756			$ 350,345	$ 375,256
Total investment costs and expenses		55,664	53,202	50,352	62,450	57,653	64,132	61,340			181,136	223,657
Total other income (loss)		20,887	(186,065)	(185,449)	8,035	(69,164)	(239,584)	(125,685)			(344,382)	(432,643)
Total other expenses		14,364	11,457	11,547	12,269	17,168	14,310	14,898			43,572	52,441
Income (loss) before income taxes		45,172	(168,054)	(158,239)	39,007	(46,199)	(186,750)	(77,167)			(218,745)	(333,485)
Income tax expense (benefit)		28	20	94	729	347	422	34			484	1,190
Net income (loss)		45,144	(168,074)	(158,333)	38,278	(46,546)	(187,172)	(77,201)			(219,229)	(334,675)
Net income (loss) attributable to noncontrolling interests		0	(7,977)	(6,676)	(2,705)	(6,071)	(6,772)	816			(5,956)	(23,429)
Net income (loss) attributable to KKR Financial Holdings LLC and subsidiaries		45,144	(160,097)	(151,657)	40,983	(40,475)	(180,400)	(78,017)			(213,273)	(311,246)
Preferred share distributions		6,891	6,891	6,891	6,891	6,891	6,891	6,891			20,673	27,564
Net income (loss) available to common shares		$ 38,253	$ (166,988)	$ (158,548)	$ 34,092	$ (47,366)	$ (187,291)	$ (84,908)			$ (233,946)	$ (338,810)
Predecessor Company
Entity Information [Line Items]
Total revenues	$ 76,652								$ 140,590	$ 217,242			$ 545,906
Total investment costs and expenses	28,055								73,770	101,825			305,705
Total other income (loss)	(16,506)								72,840	56,334			150,925
Total other expenses	34,151								31,458	65,609			97,429
Income (loss) before income taxes	(2,060)								108,202	106,142			293,697
Income tax expense (benefit)	143								19	162			467
Net income (loss)	(2,203)								108,183	105,980			293,230
Net income (loss) attributable to noncontrolling interests	0								0	0			0
Net income (loss) attributable to KKR Financial Holdings LLC and subsidiaries	(2,203)								108,183	105,980			293,230
Preferred share distributions	0								6,891	6,891			27,411
Net income (loss) available to common shares	$ (2,203)								$ 101,292	$ 99,089			$ 265,819
Net income (loss) per common share:
Basic (in dollars per share)	$ (0.01)								$ 0.49	$ 0.48			$ 1.31
Diluted (in dollars per share)	$ (0.01)								$ 0.49	$ 0.48			$ 1.31
Weighted-average number of common shares outstanding:
Basic (in shares)	204,398								204,236	204,276			202,411
Diluted (in shares)	204,398								204,236	204,276			202,411