Federal Income Taxes - Schedule of Reconciliation of Net Income to Taxable Income (Loss) (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Fourth Quarter Two Thousand Twenty One Member
Income Taxes [Line Items]
Dividends			$ 14.4
Dividends payable, month and year			2022-01
Fourth Quarter Two Thousand Twenty Two Member
Income Taxes [Line Items]
Dividends		$ 17.1
Dividends payable, month and year		2023-01
Fourth Quarter Two Thousand Twenty Three [Member]
Income Taxes [Line Items]
Dividends	$ 17.2
Dividends payable, month and year	2024-01