Shareholders' Equity Cash Dividend Restrictions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
C Cash Dividend Restrictions [Abstract]
Amount available for dividend distribution without prior approval from regulatory agency	$ 854.5
Extra-ordinary dividends received from subsidiaries	110.0	$ 140.0	$ 100.0
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries	$ 673.3	$ 614.6	$ 566.7