Related Party Transactions - Summary of Revenues, Expenses and Balance Sheet Items for EQH and Subsidiaries (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Other revenues	$ 108,409	$ 104,703	$ 97,559
Total revenues	4,445,288	3,724,186	3,575,637
Expenses:
General and administrative	555,608	485,544	484,750
Other	197,486	189,787	219,860
Total expenses	3,225,140	2,801,100	2,694,995
Balance Sheet:
Institutional investment advisory and services fees receivable	185,653	148,746
EQH
Revenues:
Other revenues	675	1,330	1,013
Total revenues	133,749	117,231	110,329
Expenses:
General and administrative	2,373	2,281	2,466
Other	3,953	5,463	3,644
Total expenses	10,876	11,696	10,066
Balance Sheet:
Institutional investment advisory and services fees receivable	8,607	8,343
Prepaid expenses	545	404
Other due to EQH and its subsidiaries	(1,534)	(1,280)
EQH Facility	(755,000)	(675,000)
Total	(747,382)	(667,533)
Investment advisory and services fees
Revenues:
Revenue subject to contracts with customers	3,194,524	2,595,436	2,472,044
Investment advisory and services fees | EQH
Revenues:
Revenue subject to contracts with customers	133,074	115,901	109,316
Distribution related
Revenues:
Revenue subject to contracts with customers	652,240	529,781	455,043
Expenses:
Commissions and distribution payments to financial intermediaries	708,117	569,283	487,965
Distribution related | EQH
Expenses:
Commissions and distribution payments to financial intermediaries	$ 4,550	$ 3,952	$ 3,956