Note 15: Disclosures About Fair Value of Financial Instruments: Schedule Of Financial Instruments Fair Value (Details) $ in Thousands	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Financial Assets | Loans Receivable
Financial Instruments Owned Carrying Amount	$ 4,050,336	$ 3,989,001
Financial Instruments, Owned, at Fair Value	$ 4,034,628	$ 3,955,786
Fair Value Hierarchy Level	3	3
Financial Assets | Mortgage Loans Held for Sale
Financial Instruments Owned Carrying Amount	$ 1,892	$ 1,650
Financial Instruments, Owned, at Fair Value	$ 1,892	$ 1,650
Fair Value Hierarchy Level	2	2
Financial Assets | Accrued Interest Receivable
Financial Instruments Owned Carrying Amount	$ 14,550	$ 13,448
Financial Instruments, Owned, at Fair Value	$ 14,550	$ 13,448
Fair Value Hierarchy Level	3	3
Financial Assets | Cash and Cash Equivalents
Financial Instruments Owned Carrying Amount	$ 206,090	$ 202,742
Financial Instruments, Owned, at Fair Value	$ 206,090	$ 202,742
Fair Value Hierarchy Level	1	1
Financial Assets | Investment in Federal Home Loan Bank Stock
Financial Instruments Owned Carrying Amount	$ 5,633	$ 12,438
Financial Instruments, Owned, at Fair Value	$ 5,633	$ 12,438
Fair Value Hierarchy Level	3	3
Financial Liabilities | Junior Subordinated Debt
Financial Instruments Owned Carrying Amount	$ 25,774	$ 25,774
Financial Instruments, Owned, at Fair Value	$ 25,774	$ 25,774
Fair Value Hierarchy Level	3	3
Financial Liabilities | Subordinated Debt
Financial Instruments Owned Carrying Amount	$ 73,951	$ 73,842
Financial Instruments, Owned, at Fair Value	$ 75,750	$ 75,188
Fair Value Hierarchy Level	2	2
Financial Liabilities | Deposits
Financial Instruments Owned Carrying Amount	$ 3,956,091	$ 3,725,007
Financial Instruments, Owned, at Fair Value	$ 3,952,867	$ 3,717,899
Fair Value Hierarchy Level	3	3
Financial Liabilities | Short-term Debt
Financial Instruments Owned Carrying Amount	$ 140,837	$ 297,978
Financial Instruments, Owned, at Fair Value	$ 140,837	$ 297,978
Fair Value Hierarchy Level	3	3
Financial Liabilities | Accrued Interest Payable
Financial Instruments Owned Carrying Amount	$ 2,933	$ 3,570
Financial Instruments, Owned, at Fair Value	$ 2,933	$ 3,570
Fair Value Hierarchy Level	3	3
Unrecognized Financial Instruments Net of Contractual Value | Letter of Credit
Financial Instruments Owned Carrying Amount	$ 142	$ 146
Financial Instruments, Owned, at Fair Value	$ 142	$ 146
Fair Value Hierarchy Level	3	3
Unrecognized Financial Instruments Net of Contractual Value | Line of Credit
Financial Instruments Owned Carrying Amount	$ 0	$ 0
Financial Instruments, Owned, at Fair Value	$ 0	$ 0
Fair Value Hierarchy Level	3	3
Unrecognized Financial Instruments Net of Contractual Value | Loan Origination Commitments
Financial Instruments Owned Carrying Amount	$ 0	$ 0
Financial Instruments, Owned, at Fair Value	$ 0	$ 0
Fair Value Hierarchy Level	3	3