Derivatives and Hedging Activities (Impact of Hedging Activity) (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments Gain (Loss)
Number of interest rate swaps held	3		3
Cash flow hedges
Derivative Instruments Gain (Loss)
Estimated reclassification of net pretax losses on cash flow hedges from accumulated other comprehensive income to earnings during the next 12 months			$ 1
Reclassification of net pretax gains, to be recorded as a reduction to interest and debt expense in the next 12 months			5
Reclassification of net pretax losses, to be recorded in net investment income in the next 12 months			6
Amount of Gain (Loss) Reclassified from Accumulated other Comprehensive Income into Income	0	0	0	0
Hedging exposure to the variability in future cash flows			21 years
Cash flow hedges | Net investment income
Derivative Instruments Gain (Loss)
Amount of Gain (Loss) Reclassified from Accumulated other Comprehensive Income into Income	(1)	(1)	(2)	(2)
Cash flow hedges | Interest and debt expense
Derivative Instruments Gain (Loss)
Amount of Gain (Loss) Reclassified from Accumulated other Comprehensive Income into Income	1	1	2	2
Fair value hedges | Fixed rate debt | Interest and debt expense
Derivative Instruments Gain (Loss)
Amount of Gain Recognized in Income on Derivatives	$ 8	$ 10	$ 16	$ 20