Loans and Leases - Schedule of Activity In The Allowance For Loan Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 51	$ 43	$ 46	$ 37
Provision for loan losses	0	5	8	11
Charge-offs	0	0	(3)	0
Ending balance	51	$ 48	51	$ 48
Loans and leases, allowance for losses	51		51		$ 46
Commercial and Financial | Senior Secured Bank Loans
Allowance for Loan and Lease Losses [Roll Forward]
Loans and leases, allowance for losses	43		43		$ 35
Commercial and Financial | Other Loans
Allowance for Loan and Lease Losses [Roll Forward]
Loans and leases, allowance for losses	$ 8		$ 8