Note 3: Loans and Allowance for Loan Losses: Financing Receivable Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Satisfactory | Loans Receivable
Loan Portfolio Internal Grading System Classification	$ 4,958,837	$ 4,518,002
Satisfactory | Land and Land Improvements
Loan Portfolio Internal Grading System Classification	39,892	39,171
Satisfactory | One- to four-family residential construction
Loan Portfolio Internal Grading System Classification	25,803	20,275
Satisfactory | Subdivision construction
Loan Portfolio Internal Grading System Classification	12,077	15,602
Satisfactory | Commercial construction
Loan Portfolio Internal Grading System Classification	1,417,166	1,068,352
Satisfactory | Owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	274,661	188,706
Satisfactory | Non-owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	119,951	117,103
Satisfactory | Commercial Real Estate
Loan Portfolio Internal Grading System Classification	1,357,987	1,218,431
Satisfactory | Other residential
Loan Portfolio Internal Grading System Classification	784,393	742,237
Satisfactory | Commercial business
Loan Portfolio Internal Grading System Classification	315,518	344,479
Satisfactory | Industrial revenue bonds
Loan Portfolio Internal Grading System Classification	13,940	21,859
Satisfactory | Automobile Loan
Loan Portfolio Internal Grading System Classification	251,824	354,588
Satisfactory | Consumer Loan
Loan Portfolio Internal Grading System Classification	56,859	62,682
Satisfactory | Home Equity Line of Credit
Loan Portfolio Internal Grading System Classification	121,134	114,860
Satisfactory | Acquired loans, net of discount
Loan Portfolio Internal Grading System Classification	167,632	209,657
Watch | Loans Receivable
Loan Portfolio Internal Grading System Classification	24,792	25,816
Watch | Land and Land Improvements
Loan Portfolio Internal Grading System Classification	4,600	4,800
Watch | One- to four-family residential construction
Loan Portfolio Internal Grading System Classification	374	518
Watch | Subdivision construction
Loan Portfolio Internal Grading System Classification	1,718	2,362
Watch | Commercial construction
Loan Portfolio Internal Grading System Classification	0	0
Watch | Owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	43	0
Watch | Non-owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	941	389
Watch | Commercial Real Estate
Loan Portfolio Internal Grading System Classification	11,061	9,909
Watch | Other residential
Loan Portfolio Internal Grading System Classification	501	1,532
Watch | Commercial business
Loan Portfolio Internal Grading System Classification	5,163	6,306
Watch | Industrial revenue bonds
Loan Portfolio Internal Grading System Classification	0	0
Watch | Automobile Loan
Loan Portfolio Internal Grading System Classification	116	0
Watch | Consumer Loan
Loan Portfolio Internal Grading System Classification	157	0
Watch | Home Equity Line of Credit
Loan Portfolio Internal Grading System Classification	118	0
Watch | Acquired loans, net of discount
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Loans Receivable
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Land and Land Improvements
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | One- to four-family residential construction
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Subdivision construction
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Commercial construction
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Non-owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Commercial Real Estate
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Other residential
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Commercial business
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Industrial revenue bonds
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Automobile Loan
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Consumer Loan
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Home Equity Line of Credit
Loan Portfolio Internal Grading System Classification	0	0
Special Mention | Acquired loans, net of discount
Loan Portfolio Internal Grading System Classification	0	0
Substandard | Loans Receivable
Loan Portfolio Internal Grading System Classification	9,622	18,645
Substandard | Land and Land Improvements
Loan Portfolio Internal Grading System Classification	0	0
Substandard | One- to four-family residential construction
Loan Portfolio Internal Grading System Classification	0	0
Substandard | Subdivision construction
Loan Portfolio Internal Grading System Classification	49	98
Substandard | Commercial construction
Loan Portfolio Internal Grading System Classification	0	0
Substandard | Owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	2,162	1,809
Substandard | Non-owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	1,546	1,976
Substandard | Commercial Real Estate
Loan Portfolio Internal Grading System Classification	2,387	6,989
Substandard | Other residential
Loan Portfolio Internal Grading System Classification	0	1,876
Substandard | Commercial business
Loan Portfolio Internal Grading System Classification	1,437	2,066
Substandard | Industrial revenue bonds
Loan Portfolio Internal Grading System Classification	0	0
Substandard | Automobile Loan
Loan Portfolio Internal Grading System Classification	1,588	2,554
Substandard | Consumer Loan
Loan Portfolio Internal Grading System Classification	334	686
Substandard | Home Equity Line of Credit
Loan Portfolio Internal Grading System Classification	100	579
Substandard | Acquired loans, net of discount
Loan Portfolio Internal Grading System Classification	19	12
Doubtful | Loans Receivable
Loan Portfolio Internal Grading System Classification	0	500
Doubtful | Land and Land Improvements
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | One- to four-family residential construction
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Subdivision construction
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Commercial construction
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Non-owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Commercial Real Estate
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Other residential
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Commercial business
Loan Portfolio Internal Grading System Classification	0	500
Doubtful | Industrial revenue bonds
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Automobile Loan
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Consumer Loan
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Home Equity Line of Credit
Loan Portfolio Internal Grading System Classification	0	0
Doubtful | Acquired loans, net of discount
Loan Portfolio Internal Grading System Classification	0	0
Unlikely to be Collected Financing Receivable | Loans Receivable
Loan Portfolio Internal Grading System Classification	4,993,251	4,562,963
Unlikely to be Collected Financing Receivable | Land and Land Improvements
Loan Portfolio Internal Grading System Classification	44,492	43,971
Unlikely to be Collected Financing Receivable | One- to four-family residential construction
Loan Portfolio Internal Grading System Classification	26,177	20,793
Unlikely to be Collected Financing Receivable | Subdivision construction
Loan Portfolio Internal Grading System Classification	13,844	18,062
Unlikely to be Collected Financing Receivable | Commercial construction
Loan Portfolio Internal Grading System Classification	1,417,166	1,068,352
Unlikely to be Collected Financing Receivable | Owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	276,866	190,515
Unlikely to be Collected Financing Receivable | Non-owner occupied one- to four-family residential
Loan Portfolio Internal Grading System Classification	122,438	119,468
Unlikely to be Collected Financing Receivable | Commercial Real Estate
Loan Portfolio Internal Grading System Classification	1,371,435	1,235,329
Unlikely to be Collected Financing Receivable | Other residential
Loan Portfolio Internal Grading System Classification	784,894	745,645
Unlikely to be Collected Financing Receivable | Commercial business
Loan Portfolio Internal Grading System Classification	322,118	353,351
Unlikely to be Collected Financing Receivable | Industrial revenue bonds
Loan Portfolio Internal Grading System Classification	13,940	21,859
Unlikely to be Collected Financing Receivable | Automobile Loan
Loan Portfolio Internal Grading System Classification	253,528	357,142
Unlikely to be Collected Financing Receivable | Consumer Loan
Loan Portfolio Internal Grading System Classification	57,350	63,368
Unlikely to be Collected Financing Receivable | Home Equity Line of Credit
Loan Portfolio Internal Grading System Classification	121,352	115,439
Unlikely to be Collected Financing Receivable | Acquired loans, net of discount
Loan Portfolio Internal Grading System Classification	$ 167,651	$ 209,669