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Fair Value Measurements - Credit Ratings (Details) - USD ($)
$ in Millions
Mar. 31, 2023
Dec. 31, 2022
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]    
Debt securities, held-to-maturity $ 71.5 $ 71.6
AA+    
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]    
Debt securities, held-to-maturity 13.4 13.4
AA    
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]    
Debt securities, held-to-maturity 0.0 0.0
AA-    
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]    
Debt securities, held-to-maturity 10.4 10.5
A    
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]    
Debt securities, held-to-maturity 13.2 13.2
A-    
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]    
Debt securities, held-to-maturity 14.1 14.1
BBB+    
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]    
Debt securities, held-to-maturity $ 20.4 $ 20.4