Investments - Other Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summarized financial information of unconsolidated entities
Total assets, unconsolidated entities	$ 158,439.7	$ 135,355.6
Total liabilities, unconsolidated entities	88,455.8	80,265.4
Total equity, unconsolidated entities	69,983.9	55,090.2
Net investment in unconsolidated entities	1,825.5	1,723.7
Total revenues, unconsolidated entities	17,802.2	15,389.4	$ 15,020.9
Net income, unconsolidated entities	7,938.3	6,542.1	4,530.1
Our share of net income of unconsolidated entities	222.5	161.6	$ 232.7
Other Types of Investments
Direct financing leases	782.9	830.7
Cash surrender value of company owned life insurance	734.1	502.6
Certain sponsored investment funds carried at fair value	$ 678.7	$ 719.7