Borrowed Funds and Mandatorily Redeemable Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) note	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Borrowed funds and mandatorily redeemable securities
Total long-term debt and mandatorily redeemable securities	$ 57,379	$ 56,232
Annual maturities of long-term debt
2016	6,296
2017	26,351
2018	917
2019	826
2020	721
Thereafter	22,268
Mandatorily redeemable securities
Interest expense	1,370	1,470	$ 1,000
Securities subject to mandatory redemption
Borrowed funds and mandatorily redeemable securities
Mandatorily redeemable securities	17,388	15,678
Federal Home Loan Bank borrowings
Borrowed funds and mandatorily redeemable securities
Long-term debt	$ 38,044	38,582
Minimum interest rate on Federal Home Loan Bank borrowings (as a percent)	1.10%
Maximum interest rate on Federal Home Loan Bank borrowings (as a percent)	6.54%
Annual maturities of long-term debt
Number of Federal Home Loan Bank borrowings, fixed rate notes | note	18
Collateral security	$ 47,560
Other long-term debt
Borrowed funds and mandatorily redeemable securities
Long-term debt	$ 1,947	$ 1,972