Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses (Schedule of Liability for Unpaid Claims and Claims Adjustment Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Liability for Claims and Claims Adjustment Expenses (Rollforward) [Abstract]
Liability for Claims and Claims Adjustment Expense	$ 149	$ 169
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	108	120
Liability for Unpaid Claims and Claims Adjustment Expense, Net	41	49
Current Year Claims and Claims Adjustment Expense	89	77
Prior Year Claims and Claims Adjustment Expense	(1)	(4)
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims	88	73
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year	(45)	(37)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years	(23)	(22)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid	(68)	(59)
Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss)	2	3
Liability for Unpaid Claims and Claims Adjustment Expense, Net	63	66
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	112	118
Liability for Claims and Claims Adjustment Expense	$ 175	$ 184