Schedule Summarizing Quarterly Operation Results (Parenthetical) (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information [Line Items]
Charge related to closed block of long-term care policies	$ 243	$ 243	$ 29
After tax impact of charge	$ 154
Impact on EPS of charge	$ 0.99