Subsequent Events (Details) - Forecast - USD ($) $ in Millions		12 Months Ended
	Apr. 09, 2020	Dec. 31, 2020
Subsequent Event [Line Items]
Impact of rate reductions on premiums		$ 90
Impact of rate reductions on management fees		$ 23
Subsequent Event
Subsequent Event [Line Items]
Estimated personal and commercial auto rate reductions	$ 200