Schedule IV - Reinsurance (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Premiums:
Ceded to other companies, premiums	$ 113	$ 146	$ 249	$ 276
Net amount	$ 7,654	$ 7,432	$ 15,400	$ 14,834