Investments (Narratives) (Details) - USD ($) $ in Millions	9 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2022
Insurance Regulatory Authorites:
Assets held by insurance regulators		$ 21.4	$ 27.1
Available for sale securities:
Fair value of sold available for sale securites	$ 147.6	352.3
Available for sale securities, realized gains	1.1	9.5
Available for sale securities, gross realized losses	0.5	$ 1.4
Other-than-temporary impairments	$ 2.2

Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

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