Note 2: Investments in Securities: Schedule of Financial Instruments Owned and Pledged as Collateral (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Public Deposit
Securities Owned and Pledged As Collateral Amortized Cost	$ 9,482	$ 10,958
Security Owned and Pledged as Collateral, Fair Value	9,802	11,490
Collateralized Borrowing Accounts
Securities Owned and Pledged As Collateral Amortized Cost	148,050	120,622
Security Owned and Pledged as Collateral, Fair Value	146,337	119,776
Other Pledged Securities
Securities Owned and Pledged As Collateral Amortized Cost	763	1,579
Security Owned and Pledged as Collateral, Fair Value	761	1,601
Securities Pledged as Collateral
Securities Owned and Pledged As Collateral Amortized Cost	158,295	133,159
Security Owned and Pledged as Collateral, Fair Value	$ 156,900	$ 132,867