Investments - Income (Loss) from Equity Method Investments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	$ 20,090	$ (839)	$ 47,880	$ 42,412
Private Equity Segment [Member] | AAA Investments [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	6	(1)	33	83
Private Equity Segment [Member] | Apollo Investment Fund IV, L.P. ("Fund IV") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment		(2)		(2)
Private Equity Segment [Member] | Apollo Investment Fund V, L.P. ("Fund V") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(1)	24	6	29
Private Equity Segment [Member] | Apollo Investment Fund VI, L.P. ("Fund VI") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(5)	(64)	1,073	2,548
Private Equity Segment [Member] | Apollo Investment Fund VII, L.P. ("Fund VII") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	11,064	(858)	31,477	23,223
Private Equity Segment [Member] | ANRP [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	152	137	163	174
Private Equity Segment [Member] | AION Capital Partners Limited [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	369		553
Private Equity Segment [Member] | APC [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	2		3
Credit Funds [Member] | Apollo Special Opportunities Managed Account, L.P. ("SOMA") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	30	(30)	414	666
Credit Funds [Member] | Apollo Value Investment Fund LP (VIF) [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(1)	(4)	6	15
Credit Funds [Member] | SVF [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(2)	(3)	1	12
Credit Funds [Member] | ACLF [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(36)	78	668	1,966
Credit Funds [Member] | Artus [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(2)	(104)	(2)	291
Credit Funds [Member] | COF I [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	563	(1,851)	4,137	7,168
Credit Funds [Member] | COF II [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(304)	522	584	2,955
Credit Funds [Member] | COF III [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(11)		(11)
Credit Funds [Member] | EPF I [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	3,079	150	2,748	794
Credit Funds [Member] | AIE II [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	349	(400)	406	503
Credit Funds [Member] | Palmetto [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	259	38	842	549
Credit Funds [Member] | AFT [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(3)	1	5	11
Credit Funds [Member] | AMTG [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	22	403	508	555
Credit Funds [Member] | AEC [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	71	(8)	147	27
Credit Funds [Member] | AESI [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	106	(31)	258	162
Credit Funds [Member] | ACSP [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	108	(67)	289	(67)
Credit Funds [Member] | AINV [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	2,037		1,410
Credit Funds [Member] | EPF II [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	23	316	86	316
Credit Funds [Member] | Apollo SK Strategic Investments, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	23		49
Credit Funds [Member] | Apollo SPN Investments I, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	501		88
Credit Funds [Member] | Apollo Tactical Income Fund Inc. ("AIF") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(10)		(5)
Credit Funds [Member] | Apollo Franklin Partnership, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(7)		(7)
Real Estate Segment [Member] | ARI [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	93	268	316	516
Real Estate Segment [Member] | AGRE U.S. Real Estate Fund, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	227	(33)	241	(86)
Real Estate Segment [Member] | CPI Capital Partners North America LP [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	16	(10)	74	(31)
Real Estate Segment [Member] | CPI Capital Partners Asia Pacific, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(6)	32	(4)	37
Real Estate Segment [Member] | Apollo GSS Holding (Cayman), L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(1)		(5)
Real Estate Segment [Member] | BEA/AGRE China Real Estate Fund, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	(8)		(8)
Other Equity Method Investments [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	8	452		5
Other Equity Method Investments [Member] | VC Holdings, L.P. Series A ("Vantium A/B") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment		(1)	13	(306)
Other Equity Method Investments [Member] | VC Holdings, L.P. Series C ("Vantium C") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	1,333	17	1,325	(133)
Other Equity Method Investments [Member] | VC Holdings, L.P. Series D ("Vantium D") [Member]
Income Loss From Equity Method Investments [Line Items]
(Loss) income from equity method investment	$ 46	$ 190	$ (1)	$ 432