Condensed Consolidated Statements of Financial Position (Parenthetical) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Equity securities	$ 2,428.2	$ 2,013.4
Mortgage loans	19,426.0	17,343.0
Real estate	1,965.6	1,797.3
Other investments	5,341.9	5,126.8
Cash and Cash Equivalents, at Carrying Value	3,145.4	2,849.8
Other investments measured at fair value under fair value option	0.0	28.5
Separate account assets	177,850.5	175,951.4
Contractholder funds	43,828.9	43,237.7
Separate account liabilities	177,850.5	175,951.4
Other liabilities	9,200.9	7,582.1
Redeemable noncontrolling interest	$ 343.3	$ 255.6
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	2,500.0	2,500.0
Common stock, issued (in shares)	484.3	481.9
Common stock, outstanding (in shares)	266.1	273.3
Treasury stock (in shares)	218.2	208.6
Aggregate consolidated variable interest entities
Equity securities	$ 789.1	$ 902.5
Mortgage loans	1,334.1	319.0
Real estate	653.3	476.8
Other investments	437.5	348.5
Cash and Cash Equivalents, at Carrying Value	52.1	28.8
Separate account assets	34,420.2	41,138.9
Contractholder funds	350.7	388.6
Separate account liabilities	34,420.2	41,138.9
Other liabilities	76.6	24.5
Redeemable noncontrolling interest	$ 309.7	$ 226.8