Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025	Jun. 30, 2025
Accumulated Other Comprehensive Income [Abstract]
Net unrealized (losses) gains on AFS investments, before taxes	$ (15.5)	$ 9.3
Deferred tax benefit (expense) on net unrealized losses	3.3	(2.0)
Total accumulated other comprehensive (loss) income	$ (12.2)	$ 7.3	$ (53.2)

Amount, after tax, of accumulated increase (decrease) in equity from transaction and other event and circumstance from nonowner source.

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+ Details