Accrued Expenses and Other Liabilities (Schedule of Accrued Expenses and Other Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Accounts Payable and Accrued Liabilities [Abstract]
Accounts Payable	$ 851	$ 649
Liability for Claims and Claims Adjustment Expense	175	149	$ 184	$ 169
Accrued Employee Benefits	156	232
Derivative Liability, Fair Value, Gross Liability	81	95
Deferred Revenue	47	56
Cash and securities collateral placed with counterparties	12	10
Other Accrued Liabilities	600	546
Accounts Payable and Accrued Liabilities	$ 1,922	$ 1,737