Investments - Other Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Summarized financial information of unconsolidated entities
Total assets	$ 292,239.6	$ 304,657.2
Total liabilities	281,934.8	288,198.9
Total stockholders' equity	10,042.8	16,125.8	$ 16,617.3	$ 14,685.8
Total revenues	17,491.6	14,262.7	14,741.7
Net income (loss)	4,852.2	1,757.4	1,428.5
Other Types of Investments
Cash surrender value of company owned life insurance	1,115.6	1,032.1
Certain sponsored investment funds carried at fair value	617.8	801.4
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Summarized financial information of unconsolidated entities
Total assets	209,547.3	177,429.0
Total liabilities	81,346.4	72,001.3
Total stockholders' equity	128,200.9	105,427.7
Total revenues	44,987.0	21,769.6	14,989.0
Net income (loss)	34,290.5	15,638.5	7,757.0
Our share of net income of unconsolidated entities	294.1	383.0	$ 143.9
Net Investment in unconsolidated entities
Summarized financial information of unconsolidated entities
Net investment in unconsolidated entities	$ 2,721.8	$ 2,162.5