Insurance Premiums (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Insurance Premiums [Abstract]
Premiums receivable	$ 792	$ 875	$ 1,051
Weighted average risk-free rate	2.70%	2.80%
Weighted average expected collection term of the premiums receivable, years	9 years 29 days	9 years 2 months 4 days
Reinsurance premiums payable	$ 38	$ 56