Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset, beginning of period	$ 618	$ 571	$ 616	$ 578
Capitalized deferred policy acquisition costs	230	221	452	428
Deferred Policy Acquisition Cost, Amortization Expense	(214)	(204)	(426)	(413)
Deferred Policy Acquisition Cost, Amortization Expense, Other	(10)	12	(18)	7
Deferred policy acquisition costs asset, end of period	624	600	624	600
Life Insurance Product Line [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset, beginning of period	221	194	228	199
Capitalized deferred policy acquisition costs	12	12	24	23
Deferred Policy Acquisition Cost, Amortization Expense	(11)	(8)	(22)	(19)
Deferred Policy Acquisition Cost, Amortization Expense, Other	(10)	12	(18)	7
Deferred policy acquisition costs asset, end of period	212	210	212	210
Consolidated Property and Casualty Insurance Entity
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset, beginning of period	397	377	388	379
Capitalized deferred policy acquisition costs	218	209	428	405
Deferred Policy Acquisition Cost, Amortization Expense	(203)	(196)	(404)	(394)
Deferred policy acquisition costs asset, end of period	$ 412	$ 390	$ 412	$ 390