Fair Value Option - Additional Information (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonaccrual Loans	$ 1,175,000,000	$ 1,305,000,000
Accruing Loans Contractually Past Due 90 days or More	34,000,000	34,000,000
Loans Receivable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonaccrual Loans	0	0
Accruing Loans Contractually Past Due 90 days or More	$ 0	$ 0