Notes Payable Principal payment obligations on notes payable outstanding (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Capitalization, Long-term Debt [Line Items]
Repayments of Notes Payable			$ 20.0	$ 15.0	$ 0.0
Dekania Surplus Note [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Notes Payable					10.0
Repayments of Notes Payable				10.2
Alesco Surplus Note [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Notes Payable					$ 10.0
Repayments of Notes Payable				10.2
Federal Home Loan Bank [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Repayments of Notes Payable	$ 15.0	$ 5.0		$ 15.0