Concentrations of Credit Risk (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Concentration Risk [Line Items]
Total Residential Real Estate	$ 6,413.5	$ 6,319.9
Florida
Concentration Risk [Line Items]
Total Residential Real Estate	1,603.2	1,554.8
California
Concentration Risk [Line Items]
Total Residential Real Estate	1,508.1	1,449.0
Illinois
Concentration Risk [Line Items]
Total Residential Real Estate	686.9	738.8
New York
Concentration Risk [Line Items]
Total Residential Real Estate	498.7	449.4
Colorado
Concentration Risk [Line Items]
Total Residential Real Estate	364.2	309.0
Texas
Concentration Risk [Line Items]
Total Residential Real Estate	312.4	320.3
All other
Concentration Risk [Line Items]
Total Residential Real Estate	$ 1,440.0	$ 1,498.6