Nature of Operations and Summary of Significant Accounting Policies Federal Home Loan Bank Stock (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Investment Holdings [Line Items] | ||
| Investment in Federal Home Loan Bank and Federal Reserve Bank stock, at cost | $ 1,100 | $ 1,800 |
| Federal Reserve Bank Stock | 1,100 | 1,100 |
| FHLB Stock | ||
| Investment Holdings [Line Items] | ||
| Other than temporary impairment losses, investments | $ 0 | $ 0 |