NET INCOME (LOSS) PER SHARE OF CLASS A COMMON STOCK - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands												3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2020	May 29, 2020	Apr. 15, 2020	Feb. 28, 2020	Nov. 29, 2019	Sep. 26, 2019	Aug. 15, 2019	Jul. 31, 2019	May 02, 2019	Apr. 12, 2019	Feb. 28, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Numerator:
Dividends	$ (212,100)	$ (181,900)	$ (43,000)	$ (361,200)	$ (201,600)	$ (17,800)	$ (4,100)	$ (201,400)	$ (185,200)	$ (45,400)	$ (226,600)			$ (798,200)		$ (882,100)
Earnings allocable to participating securities												$ (5,853)	$ (11,440)	0	$ (16,003)
RSUs
Numerator:
Dividends												(4,008)	(4,450)	(14,863)	(13,524)
Dilution effect on distributable income attributable to unvested RSUs												$ 0	$ 1,200	$ 0	$ 2,355
Denominator:
Dilution effect of unvested RSUs (in shares)												0	1,843,680	0	1,657,627
Class A Common Stock
Numerator:
Net income (loss) attributable to Apollo Global Management, Inc. Class A Common Stockholders												$ 263,236	$ 354,106	$ (304,982)	$ 649,658
Dividends	$ (112,100)	$ (96,200)	$ 0	$ (205,600)	$ (111,500)	$ 0	$ 0	$ (100,400)	$ (92,200)	$ 0	$ (113,300)	(112,075)	(100,355)	(413,858)	(305,901)	$ (417,400)
Undistributed income (loss) attributable to Class A Common Stockholders: Basic												141,300	237,861	(733,703)	314,230
Undistributed income (loss) attributable to Class A Common Stockholders: Diluted												$ 141,300	$ 239,061	$ (733,703)	$ 316,585
Denominator:
Weighted Average Number of Shares of Class A Common Stock Outstanding – Basic (in shares)												227,771,678	205,797,643	227,395,847	202,087,827
Weighted Average Number of Shares of Class A Common Stock Outstanding – Diluted (in shares)												227,771,678	207,641,323	227,395,847	203,745,454
Net Income per share of Class A Common Stock: Basic
Distributed Income (in USD per share)												$ 0.49	$ 0.50	$ 1.80	$ 1.52
Undistributed Income (Loss) (in USD per share)												0.62	1.14	(3.21)	1.55
Net Income (Loss) Available to Class A Common Stock – Basic (in USD per share)												1.11	1.64	(1.41)	3.07
Net Income per share of Class A Common Stock: Diluted
Distributed Income (in USD per share)												0.49	0.49	1.80	1.51
Undistributed Income (Loss) (in USD per share)												0.62	1.14	(3.21)	1.55
Net Income (Loss) Available to Class A Common Stock – Diluted (in USD per share)												$ 1.11	$ 1.63	$ (1.41)	$ 3.06