Premiums Receivable and Other Insurance Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Premiums Receivable Disclosure [Abstract]
Prepaid Reinsurance Premiums	$ 554	$ 551
Reinsurance Recoverables on Unpaid Losses, Gross	90	88
Reinsurance Recoverables on Paid Losses, Gross	23	23
Premiums Receivable, Net	100	105
Deferred Policy Acquisition Cost	1,912	1,791
Premiums receivable and other insurance assets	$ 2,679	$ 2,558