Schedule V (details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance recoverables [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period	$ 203	$ 239	$ 258
Valuation and qualifying accounts, charged to other accounts			2
Valuation and qualifying accounts, deductions	46	36	21
Valuation and qualifying accounts, balance at end of period	157	203	239
Allowance for uncollectible premiums receivable from underwriting activities [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period	70	75	76
Valuation and qualifying accounts, charged to costs and expenses	38	44	48
Valuation and qualifying accounts, deductions	43	49	49
Valuation and qualifying accounts, balance at end of period	65	70	75
Allowance for uncollectible deductibles [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period	36	39	41
Valuation and qualifying accounts, charged to costs and expenses	3		1
Valuation and qualifying accounts, deductions	4	3	3
Valuation and qualifying accounts, balance at end of period	$ 35	$ 36	$ 39