INVESTMENTS - Schedule of Credit Ratings (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 519.1	$ 383.1
Fair Value	$ 517.1	$ 387.0
AFS securities \| Credit rating
Debt Securities, Available-for-sale [Line Items]
% of Total Fair Value	100.00%	100.00%
AAA
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 104.7	$ 81.5
Fair Value	$ 104.2	$ 82.1
AAA \| AFS securities \| Credit rating
Debt Securities, Available-for-sale [Line Items]
% of Total Fair Value	20.20%	21.20%
AA+, AA, AA-
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 218.2	$ 171.4
Fair Value	$ 217.4	$ 173.3
AA+, AA, AA- \| AFS securities \| Credit rating
Debt Securities, Available-for-sale [Line Items]
% of Total Fair Value	42.00%	44.80%
A+, A, A-
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 155.8	$ 107.7
Fair Value	$ 155.2	$ 108.8
A+, A, A- \| AFS securities \| Credit rating
Debt Securities, Available-for-sale [Line Items]
% of Total Fair Value	30.00%	28.10%
BBB+, BBB, BBB-
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 40.4	$ 22.5
Fair Value	$ 40.3	$ 22.8
BBB+, BBB, BBB- \| AFS securities \| Credit rating
Debt Securities, Available-for-sale [Line Items]
% of Total Fair Value	7.80%	5.90%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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