Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Line Items]
Damages sought	$ 834
Damages resolved by rescission settlement	800
Commitment to fund limited partnership investments	65
Commitment to fund U.S. commercial mortgage loan investments	29
Commitment to fund private placement investments	109
Curtailment and denial practices
Commitments and Contingencies Disclosure [Line Items]
Damages sought	150
Rivermont Insurance Company I
Commitments and Contingencies Disclosure [Line Items]
One time commitment fee	2
Maximum potential amount of future obligation	$ 95