Components for Mortgage Loan Portfolio (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 FICO_Score
Schedule Of Available For Sale Securities [Line Items]
Unpaid principal balance	$ 30,792
Minimum
Schedule Of Available For Sale Securities [Line Items]
Unpaid principal balance	447
Interest rate	2.75%
Maturity	2044-06
FICO score at loan origination	705
Loan-to-value ratio at loan origination	28.00%
Maximum
Schedule Of Available For Sale Securities [Line Items]
Unpaid principal balance	1,332
Interest rate	3.75%
Maturity	2044-12
FICO score at loan origination	813
Loan-to-value ratio at loan origination	80.00%
Weighted Average
Schedule Of Available For Sale Securities [Line Items]
Unpaid principal balance	$ 790
Interest rate	3.43%
Maturity	2044-09
FICO score at loan origination	762
Loan-to-value ratio at loan origination	65.00%