CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Investments and receivables at fair value	$ 2,757.8	$ 1,865.8
Class A
Common stock, nominal value (in dollars per share)	$ 0.01	$ 0.01
Common stock, issued (in shares)	174,310,558	181,348,114
Common stock, outstanding (in shares)	174,310,558	181,348,114
Class B
Common stock, nominal value (in dollars per share)	$ 0.01	$ 0.01
Common stock, issued (in shares)	12,930,839	12,561,444
Common stock, outstanding (in shares)	12,930,839	12,561,444
Class C
Common stock, nominal value (in dollars per share)	$ 0.01	$ 0.01
Common stock, issued (in shares)	340,114,729	386,588,921
Common stock, outstanding (in shares)	340,114,729	386,588,921