Securities - OTTI Significant Assumptions (Details) - Non-agency residential	Mar. 31, 2016
Weighted Average
Significant Assumptions:
Annual prepayment speed	13.10%
Loss severity	29.90%
Life default rate	23.10%
Weighted Average \| Prime
Significant Assumptions:
Loss severity	26.90%
Life default rate	14.80%
Weighted Average \| Alt-A Loan
Significant Assumptions:
Loss severity	28.70%
Life default rate	24.90%
Weighted Average \| Subprime
Significant Assumptions:
Loss severity	40.20%
Life default rate	24.10%
10th Percentile
Significant Assumptions:
Annual prepayment speed	4.20%
Loss severity	12.20%
Life default rate	0.70%
90th Percentile
Significant Assumptions:
Annual prepayment speed	26.40%
Loss severity	30.50%
Life default rate	81.70%