Contingencies and Other Matters - Regulatory Matters (Details) (Unfavorable Regulatory Action [Member], USD $)	3 Months Ended
	Mar. 31, 2013
Loss Contingencies [Line Items]
Pre-tax charge in connection with a regulatory matter	$ (77,000,000)
After-tax charge in connection with a regulatory matter	51,000,000
Prior claims [Member]
Loss Contingencies [Line Items]
Pre-tax charge in connection with a regulatory matter	(48,000,000)
Prior claims [Member] | Regulatory Surcharges [Member]
Loss Contingencies [Line Items]
Pre-tax charge in connection with a regulatory matter	(750,000)
Prior claims [Member] | Claims Handling Expenses [Member]
Loss Contingencies [Line Items]
Pre-tax charge in connection with a regulatory matter	(9,500,000)
Prior claims [Member] | Fines [Member]
Loss Contingencies [Line Items]
Pre-tax charge in connection with a regulatory matter	(925,000)
Current Claims [Member]
Loss Contingencies [Line Items]
Pre-tax charge in connection with a regulatory matter	$ (29,000,000)