Schedule IV - Reinsurance (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Premiums:
Ceded to other companies, premiums	$ 168	$ 118	$ 444	$ 387
Net amount	$ 7,347	$ 6,832	$ 22,181	$ 20,308