Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Accounts and accrued income receivable, allowances	$ 20.9	$ 21.3
Pledged securities included in debt securities	96.8	86.0
Debt securities, amortized costs	$ 8,413.5	$ 9,169.6
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	500,000	500,000
Preferred stock, outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares outstanding	103,200,000	103,200,000