Reinsurance - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Puerto Rico
Ceded Credit Risk [Line Items]
Net par exposures reassumed	$ 118.0
AG Re
Ceded Credit Risk [Line Items]
Amounts could be required to pay if third party exercised right to recapture business	40.0
AGC
Ceded Credit Risk [Line Items]
Amounts could be required to pay if third party exercised right to recapture business	238.0
Standard & Poor's, A Rating | Uncollateralized
Ceded Credit Risk [Line Items]
Guaranty liabilities	0.0
AM Best, A- Rating | Uncollateralized
Ceded Credit Risk [Line Items]
Guaranty liabilities	$ 13.0