Fair Value Measurements (Asset Fair Value Measurements Using Significant Unobservable Inputs (Level 3)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 5	$ 25
Total gains or losses (realized/unrealized):
Included in other comprehensive income	0	4
Purchases	1	1
Sales	(1)	(6)
Transfers into Level 3	0	1
Transfers out of Level 3	(1)	(20)
Ending balance	4	5
Corporate Fixed Maturities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	3	18
Total gains or losses (realized/unrealized):
Included in other comprehensive income	0	2
Sales	0	(4)
Transfers into Level 3	0	1
Transfers out of Level 3	1	(14)
Ending balance	2	3
States, Municipalities And Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	1	3
Total gains or losses (realized/unrealized):
Sales	1	(2)
Ending balance	0	1
Preferred Stock [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	1	4
Total gains or losses (realized/unrealized):
Included in other comprehensive income	0	2
Purchases	1	1
Transfers out of Level 3	0	(6)
Ending balance	$ 2	$ 1