Derivative Instruments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Derivative Instruments
Maximum length of time hedged in cash flow hedge (in years)	14 years 0 months 0 days
Notional of credit derivative	$ 315	$ 369
Fair value of credit derivative liability	1.0	2.0
Maximum exposure to loss from externally-managed investments	0	7
Pruco Re and Prudential Insurance FV of embedded derivatives related to reinsurance recoverables	1,823	1,748
FV Of Embedded Derivatives Included In Future Policy Benefits	1,887	1,784
FV Of Embedded Derivatives Included In Fixed Maturities AFS	0	3
Credit protection purchased notional amounts	30	30
Credit derivative protection purchased fair value	$ 2	$ 2