Investments - Other Investments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Income Loss From Equity Method Investments [Line Items]
Other investments	$ 397,358	$ 393,684
AAA Investments [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments % of Ownership	72.00%	77.00%
Private Equity Segment [Member] | AAA Investments [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	997	998
Other investments % of Ownership	0.058%	0.057%
Private Equity Segment [Member] | Fund IV [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	9	9
Other investments % of Ownership	0.015%	0.015%
Private Equity Segment [Member] | Fund V [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	113	173
Other investments % of Ownership	0.017%	0.014%
Private Equity Segment [Member] | Fund VI [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	8,746	9,814
Other investments % of Ownership	0.094%	0.094%
Private Equity Segment [Member] | Fund VII [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	158,104	164,773
Other investments % of Ownership	1.28%	1.316%
Private Equity Segment [Member] | ANRP [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	2,782	2,355
Other investments % of Ownership	0.832%	0.903%
Private Equity Segment [Member] | AION [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	1,178	625
Other investments % of Ownership	10.00%	10.00%
Private Equity Segment [Member] | APC [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	19	17
Other investments % of Ownership	0.059%	0.058%
Credit Funds [Member] | Apollo Special Opportunities Managed Account, L.P. ("SOMA") [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	6,298	5,887
Other investments % of Ownership	0.826%	0.643%
Credit Funds [Member] | Apollo Value Investment Fund LP (VIF) [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	148	141
Other investments % of Ownership	0.105%	0.093%
Credit Funds [Member] | SVF [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	23	137
Other investments % of Ownership	0.078%	0.076%
Credit Funds [Member] | ACLF [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	9,723	9,281
Other investments % of Ownership	2.573%	2.579%
Credit Funds [Member] | Artus [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	665	667
Other investments % of Ownership	6.156%	6.156%
Credit Funds [Member] | COF I [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	30,210	39,416
Other investments % of Ownership	1.918%	1.924%
Credit Funds [Member] | COF II [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	10,362	19,654
Other investments % of Ownership	1.404%	1.429%
Credit Funds [Member] | COF III [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	526
Other investments % of Ownership	2.439%
Credit Funds [Member] | EPF I [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	21,520	18,329
Other investments % of Ownership	1.363%	1.363%
Credit Funds [Member] | AIE II [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	6,734	7,207
Other investments % of Ownership	2.269%	2.205%
Credit Funds [Member] | Palmetto [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	14,491	13,614
Other investments % of Ownership	1.186%	1.186%
Credit Funds [Member] | AFT [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	103	98
Other investments % of Ownership	0.034%	0.034%
Credit Funds [Member] | AMTG [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	4,527	4,380
Other investments % of Ownership	0.623%	0.811%
Credit Funds [Member] | AEC [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	2,070	1,604
Other investments % of Ownership	1.061%	1.079%
Credit Funds [Member] | AESI [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	3,368	3,076
Other investments % of Ownership	1.006%	0.991%
Credit Funds [Member] | ACSP [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	7,484	5,327
Other investments % of Ownership	2.456%	2.457%
Credit Funds [Member] | AINV [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	53,172	51,761
Other investments % of Ownership	3.095%	2.955%
Credit Funds [Member] | EPF II [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	11,764	5,337
Other investments % of Ownership	2.268%	1.316%
Credit Funds [Member] | SK [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	1,449	1,002
Other investments % of Ownership	0.992%	0.988%
Credit Funds [Member] | Apollo SPN Investments I, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	2,611	90
Other investments % of Ownership	0.845%	0.083%
Credit Funds [Member] | CION Investment Corporation [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	1,000	1,000
Other investments % of Ownership	2.90%	22.207%
Credit Funds [Member] | AIF [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	95
Other investments % of Ownership	0.036%
Credit Funds [Member] | Apollo Franklin Partnership, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	4,993
Other investments % of Ownership	9.099%
Real Estate Segment [Member] | ARI [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	11,737	11,469
Other investments % of Ownership	1.50%	2.729%
Real Estate Segment [Member] | AGRE U.S. Real Estate Fund, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	10,873	5,210
Other investments % of Ownership	1.845%	1.845%
Real Estate Segment [Member] | CPI Capital Partners North America LP [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	334	455
Other investments % of Ownership	0.414%	0.413%
Real Estate Segment [Member] | CPI Capital Partners Europe [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	5	5
Other investments % of Ownership	0.001%	0.001%
Real Estate Segment [Member] | CPI Capital Partners Asia Pacific, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	171	186
Other investments % of Ownership	0.039%	0.039%
Real Estate Segment [Member] | Apollo GSS Holding (Cayman), L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	3,013	2,428
Other investments % of Ownership	4.946%	4.621%
Real Estate Segment [Member] | BEA/AGRE China Real Estate Fund, L.P. [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	72
Other investments % of Ownership	1.031%
Other Equity Method Investments [Member] | Vantium A/B [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	67	54
Other investments % of Ownership	6.45%	6.45%
Other Equity Method Investments [Member] | Vantium C [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	3,870	5,172
Other investments % of Ownership	2.071%	2.071%
Other Equity Method Investments [Member] | Vantium D [Member]
Income Loss From Equity Method Investments [Line Items]
Other investments	$ 1,932	$ 1,933
Other investments % of Ownership	6.345%	6.345%