Schedule IV - Reinsurance (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Premiums:
Ceded to other companies, premiums	$ 131	$ 168	$ 380	$ 444
Net amount	$ 7,605	$ 7,347	$ 23,005	$ 22,181