| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | GREAT SOUTHERN BANCORP, INC. |
| Entity Central Index Key | 0000854560 |
| Pay vs Performance Disclosure | 12 Months Ended | |||
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | ||
| Pay vs Performance Disclosure [Table] | ||||
| Pay vs Performance [Table Text Block] | Pay Versus Performance As required by the Dodd-Frank Act and the SEC’s implementing rules, we are providing the following information about the relationship between executive compensation actually paid and certain measures of financial performance. For further information concerning the Company’s compensation philosophy and how the Company seeks to align executive compensation with its performance, see the “Compensation Discussion and Analysis” section above. The following table sets forth information concerning the compensation of our named executive officers (“NEOs”) for each of the fiscal years ended December 31, 2022, 2021 and 2020 and our financial performance for each fiscal year: Value of Initial Fixed Summary Compensation Table Total for PEO(1) Compensation Actually Paid to PEO(2) Average Summary Compensation Table Total for Non-PEO NEOs(3) Average Compensation Actually Paid to Non-PEO NEOs(4) Total Shareholder Return(5) Peer Group Total Shareholder Return(6) Net Income (in thousands) (7) Diluted Earnings Per Common Share(8) 2022 $ 1,598,535 $ 1,671,534 $ 551,349 $ 612,690 $ 104.07 $ 98.03 $ 75,948 $ 6.02 2021 1,577,503 1,744,711 518,447 614,131 100.94 113.59 74,627 5.46 2020 1,517,539 1,107,789 551,353 336,824 81.25 85.98 59,313 4.21 (1) Represents the total compensation of our principal executive officer (“PEO”), Joseph W. Turner, as reported in the Summary Compensation Table (“SCT”) for each year indicated. Refer to the “Summary Compensation Table” above. Mr. J. Turner served as our PEO during those years. (2) Represents the amount of “compensation actually paid” to Mr. J. Turner, as computed in accordance with Item 402(v) of Regulation S-K. The amounts do not reflect the actual amount of compensation earned by or paid to Mr. J. Turner during the applicable year. In accordance with the requirements of Item 402(v) of Regulation S-K, the following adjustments were made to Mr. J. Turner’s total compensation for each year to determine the compensation actually paid: (3) Represents the average of the total compensation of each of our non-PEO NEOs as reported in the SCT for each year indicated. The non-PEO NEOs included in this calculation for each year are as follows: William V. Turner, Rex A. Copeland, Kevin L. Baker and John M. Bugh. (4) Represents the average of the total compensation actually paid to our named non-PEO NEOs as reported in the SCT, as computed in accordance with Item 402(v) of Regulation S-K. The amounts do not reflect the actual amount of compensation earned by or paid to the non-PEO NEOs during the applicable year. In accordance with the requirements of Item 402(v) of Regulation S-K, the following adjustments were made to average total compensation for the non-PEO NEOs as a group for each year to determine the compensation actually paid: (5) Represents the cumulative three-year total return to shareholders of our common stock and assumes that the value of the investment was $100 on December 31, 2019 and that the subsequent dividends were reinvested. The stock price performance included in this column is not necessarily indicative of future stock price performance. (6) Represents a cumulative three-year total return to shareholders of a peer group calculated using the same method described in footnote (5). For all years listed, the peer group used is the S&P U.S. BMI Banks Midwest Region Index. (7) Represents our reported net income reflected in the Company’s audited financial statements for each year indicated. (8) Represents our diluted earnings per common share, for each year indicated, which we believe represents the most important financial performance measure that was used to link compensation actually paid to our PEO and non-PEO NEOs for the most recent fiscal year to Company performance. | |||
| Named Executive Officers, Footnote [Text Block] | Represents the total compensation of our principal executive officer (“PEO”), Joseph W. Turner, as reported in the Summary Compensation Table (“SCT”) for each year indicated. Refer to the “Summary Compensation Table” above. Mr. J. Turner served as our PEO during those years. | |||
| PEO Total Compensation Amount | [1] | $ 1,598,535 | $ 1,577,503 | $ 1,517,539 |
| PEO Actually Paid Compensation Amount | [2] | $ 1,671,534 | 1,744,711 | 1,107,789 |
| Adjustment To PEO Compensation, Footnote [Text Block] | Reconciliation of PEO SCT Total and Compensation Actually Paid 2022 2021 2020 Total compensation as reported in SCT $ 1,598,535 $ 1,577,503 $ 1,517,539 Pension values reported in SCT for covered fiscal year --- (14,000 ) (258,000 ) Pension value attributable to covered fiscal year’s service and any change in pension value attributable to plan amendments made in covered fiscal year 40,000 39,000 34,000 Fair value of equity awards granted during covered fiscal year (105,144 ) (89,590 ) (54,750 ) Fair value of equity awards granted in covered fiscal year and that were unvested at end of such covered fiscal year - valued at year-end 110,370 103,075 94,125 Change in fair value from end of prior fiscal year to end of covered fiscal year for awards made in prior fiscal years that were unvested at end of current fiscal year 19,565 102,823 (152,630 ) Change in fair value from end of prior fiscal year to vesting date for awards made in prior fiscal years that vested during covered fiscal year 8,208 25,900 (72,495 ) Total compensation actually paid to PEO $ 1,671,534 $ 1,744,711 $ 1,107,789 | |||
| Non-PEO NEO Average Total Compensation Amount | [3] | $ 551,349 | 518,447 | 551,353 |
| Non-PEO NEO Average Compensation Actually Paid Amount | [4] | $ 612,690 | 614,131 | 336,824 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | Reconciliation of Non-PEO NEOs SCT Total and Compensation Actually Paid 2022 2021 2020 Total compensation as reported in SCT $ 551,349 $ 518,447 $ 551,353 Pension values reported in SCT for covered fiscal year --- (38,333 ) (128,000 ) Pension value attributable to covered fiscal year’s service and any change in pension value attributable to plan amendments made in covered fiscal year 38,500 37,500 32,500 Fair value of equity awards granted during covered fiscal year (74,814 ) (63,580 ) (38,325 ) Fair value of equity awards granted in covered fiscal year and that were unvested at end of such covered fiscal year - valued at year-end 78,533 73,150 65,888 Change in fair value from end of prior fiscal year to end of covered fiscal year for awards made in prior fiscal years that were unvested at end of current fiscal year 13,695 70,055 (100,476 ) Change in fair value from end of prior fiscal year to vesting date for awards made in prior fiscal years that vested during covered fiscal year 5,427 16,892 (46,116 ) Total average compensation actually paid to non-PEO NEOs $ 612,690 $ 614,131 $ 336,824 | |||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | ||||
| Compensation Actually Paid vs. Net Income [Text Block] | ||||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | ||||
| Total Shareholder Return Vs Peer Group [Text Block] | ||||
| Tabular List [Table Text Block] | The following list presents the most important financial measures, as determined by the Compensation Committee, used by the Company to link compensation actually paid to our NEOs, for fiscal year 2022, to the Company’s performance: ● Diluted earnings per common share ● Comparison of actual performance to budgeted expectations ● Return on average assets ● Return on average tangible common equity ● Pre-provision net revenue ● Net interest margin ● Net charge-off ratio | |||
| Total Shareholder Return Amount | [5] | $ 104.07 | 100.94 | 81.25 |
| Peer Group Total Shareholder Return Amount | [6] | 98.03 | 113.59 | 85.98 |
| Net Income (Loss) | [7] | $ 75,948,000 | $ 74,627,000 | $ 59,313,000 |
| Company Selected Measure Amount | [8] | 6.02 | 5.46 | 4.21 |
| Measure [Axis]: 1 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Diluted earnings per common share | |||
| Measure [Axis]: 2 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Comparison of actual performance to budgeted expectations | |||
| Measure [Axis]: 3 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Return on average assets | |||
| Measure [Axis]: 4 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Return on average tangible common equity | |||
| Measure [Axis]: 5 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Pre-provision net revenue | |||
| Measure [Axis]: 6 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Net interest margin | |||
| Measure [Axis]: 7 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Net charge-off ratio | |||
| Total compensation as reported in SCT [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | $ 1,598,535 | $ 1,577,503 | $ 1,517,539 | |
| Non-PEO NEO Average Compensation Actually Paid Amount | 551,349 | 518,447 | 551,353 | |
| Pension values reported in SCT for covered fiscal year [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | (14,000) | (258,000) | ||
| Non-PEO NEO Average Compensation Actually Paid Amount | (38,333) | (128,000) | ||
| Pension value attributable to covered fiscal year’s service and any change in pension value attributable to plan amendments made in covered fiscal year [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | 40,000 | 39,000 | 34,000 | |
| Non-PEO NEO Average Compensation Actually Paid Amount | 38,500 | 37,500 | 32,500 | |
| Fair value of equity awards granted during covered fiscal year [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | (105,144) | (89,590) | (54,750) | |
| Non-PEO NEO Average Compensation Actually Paid Amount | (74,814) | (63,580) | (38,325) | |
| Fair value of equity awards granted in covered fiscal year and that were unvested at end of such covered fiscal year - valued at year-end [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | 110,370 | 103,075 | 94,125 | |
| Non-PEO NEO Average Compensation Actually Paid Amount | 78,533 | 73,150 | 65,888 | |
| Change in fair value from end of prior fiscal year to end of covered fiscal year for awards made in prior fiscal years that were unvested at end of current fiscal year [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | 19,565 | 102,823 | (152,630) | |
| Non-PEO NEO Average Compensation Actually Paid Amount | 13,695 | 70,055 | (100,476) | |
| Change in fair value from end of prior fiscal year to vesting date for awards made in prior fiscal years that vested during covered fiscal year [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | 8,208 | 25,900 | (72,495) | |
| Non-PEO NEO Average Compensation Actually Paid Amount | 5,427 | 16,892 | (46,116) | |
| Total compensation actually paid to PEO [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | 1,671,534 | 1,744,711 | 1,107,789 | |
| Total average compensation actually paid to non-PEO NEOs [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 612,690 | $ 614,131 | $ 336,824 | |
| [1]Represents the total compensation of our principal executive officer (“PEO”), Joseph W. Turner, as reported in the Summary Compensation Table (“SCT”) for each year indicated. Refer to the “Summary Compensation Table” above. Mr. J. Turner served as our PEO during those years. | ||||
