| 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 | Merchants Bancorp |
| Entity Central Index Key | 0001629019 |
| 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 Table Value of initial fixed $100 Year Summary Compensation Average Average Total Peer group Net income Return 2022 (4) $1,908,889 $2,317,600 $3,038,319 $3,227,061 $192 $99 $219,721,000 17.21% 2021 (5) $1,549,064 $2,159,020 $4,922,427 $5,895,969 $246 $120 $227,104,000 22.07% 2020 (6) $1,578,683 $1,842,387 $2,984,136 $3,225,454 $143 $87 $180,533,000 25.09% (1) Our Chief Executive Officer for each of 2022, 2021, and 2020 was Mr. Petrie. (2) Our Non-Chief Executive Officers for 2022 were Messrs. Dunlap, Dury, Macke, and Schroeter. Our Non-Chief Executive Officers for 2021 and 2020 were Messrs. Dunlap and Dury. (3) The peer group used was the Nasdaq Bank Index. (4) The compensation actually paid for Principal Executive Officer and our Non- Principal Executive Officers in 2022 includes portions of equity awards from 2021, 2020, and 2019 that vested that year. (5) The compensation actually paid for Principal Executive Officer and our Non- Principal Executive Officers in 2021 includes portions of equity awards from 2020, 2019, and 2018 that vested that year. (6) The compensation actually paid for Principal Executive Officer and our Non- Principal Executive Officers in 2020 includes portions of equity awards from 2019, 2018, and 2017 that vested that year. The following table reconciles the Summary Compensation Table to the Pay Versus Performance Table above. Reconciliation: CEO Non-CEO Executive Officers (Averages) Year 2022 2021 2020 2022 2021 2020 Summary Compensation Table Total Compensation $ 1,908,889 $ 1,549,064 $ 1,578,683 $ 3,038,319 $ 4,922,427 $ 2,984,136 Less: Grant Date Value of Stock Awards in Fiscal Year $ (858,507 ) $ (728,014 ) $ (656,264 ) $ (289,006 ) $ (400,405 ) $ (319,391 ) Add: Changes in Fair Value of Outstanding and Unvested Stock Awards Granted in Prior Year and Fiscal Year $ 1,267,218 $ 1,337,970 $ 919,968 $ 477,747 $ 1,373,946 $ 560,709 Compensation Actually Paid $ 2,317,600 $ 2,159,020 $ 1,842,387 $ 3,227,061 $ 5,895,969 $ 3,225,454 | ||
| Company Selected Measure Name | Return on average equity | ||
| Named Executive Officers, Footnote [Text Block] | (1) Our Chief Executive Officer for each of 2022, 2021, and 2020 was Mr. Petrie. (2) Our Non-Chief Executive Officers for 2022 were Messrs. Dunlap, Dury, Macke, and Schroeter. Our Non-Chief Executive Officers for 2021 and 2020 were Messrs. Dunlap and Dury. | ||
| Peer Group Issuers, Footnote [Text Block] | (3) The peer group used was the Nasdaq Bank Index. | ||
| PEO Total Compensation Amount | $ 1,908,889 | $ 1,549,064 | $ 1,578,683 |
| PEO Actually Paid Compensation Amount | $ 2,317,600 | 2,159,020 | 1,842,387 |
| Adjustment To PEO Compensation, Footnote [Text Block] | The following table reconciles the Summary Compensation Table to the Pay Versus Performance Table above. Reconciliation: CEO Non-CEO Executive Officers (Averages) Year 2022 2021 2020 2022 2021 2020 Summary Compensation Table Total Compensation $ 1,908,889 $ 1,549,064 $ 1,578,683 $ 3,038,319 $ 4,922,427 $ 2,984,136 Less: Grant Date Value of Stock Awards in Fiscal Year $ (858,507 ) $ (728,014 ) $ (656,264 ) $ (289,006 ) $ (400,405 ) $ (319,391 ) Add: Changes in Fair Value of Outstanding and Unvested Stock Awards Granted in Prior Year and Fiscal Year $ 1,267,218 $ 1,337,970 $ 919,968 $ 477,747 $ 1,373,946 $ 560,709 Compensation Actually Paid $ 2,317,600 $ 2,159,020 $ 1,842,387 $ 3,227,061 $ 5,895,969 $ 3,225,454 | ||
| Non-PEO NEO Average Total Compensation Amount | $ 3,038,319 | 4,922,427 | 2,984,136 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 3,227,061 | 5,895,969 | 3,225,454 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | The following table reconciles the Summary Compensation Table to the Pay Versus Performance Table above. Reconciliation: CEO Non-CEO Executive Officers (Averages) Year 2022 2021 2020 2022 2021 2020 Summary Compensation Table Total Compensation $ 1,908,889 $ 1,549,064 $ 1,578,683 $ 3,038,319 $ 4,922,427 $ 2,984,136 Less: Grant Date Value of Stock Awards in Fiscal Year $ (858,507 ) $ (728,014 ) $ (656,264 ) $ (289,006 ) $ (400,405 ) $ (319,391 ) Add: Changes in Fair Value of Outstanding and Unvested Stock Awards Granted in Prior Year and Fiscal Year $ 1,267,218 $ 1,337,970 $ 919,968 $ 477,747 $ 1,373,946 $ 560,709 Compensation Actually Paid $ 2,317,600 $ 2,159,020 $ 1,842,387 $ 3,227,061 $ 5,895,969 $ 3,225,454 | ||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | CAP and Cumulative TSR / Cumulative TSR of the Peer Group | ||
| Compensation Actually Paid vs. Net Income [Text Block] | CAP and the Company’s Net Income | ||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | CAP and Return on Average Equity | ||
| Tabular List [Table Text Block] | The most important financial performance measures we used in 2022 to set the compensation for our Principal Executive Officer and our Non-Principal Executive Officers were revenue growth, earnings per common share, and return on average equity. | ||
| Total Shareholder Return Amount | $ 192 | 246 | 143 |
| Peer Group Total Shareholder Return Amount | 99 | 120 | 87 |
| Net Income (Loss) | $ 219,721,000 | $ 227,104,000 | $ 180,533,000 |
| Company Selected Measure Amount | 17.21 | 22.07 | 25.09 |
| PEO Name | Mr. Petrie. | ||
| Measure [Axis]: 1 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | revenue growth, | ||
| Measure [Axis]: 2 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | earnings per common share | ||
| Measure [Axis]: 3 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | return on average equity. | ||
| PEO [Member] | Grant Date Value Of Stock Awards In Fiscal Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | $ (858,507) | $ (728,014) | $ (656,264) |
| PEO [Member] | Changes In Fair Value Of Outstanding And Unvested Stock Awards Granted In Prior Year And Fiscal Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 1,267,218 | 1,337,970 | 919,968 |
| Non-PEO NEO [Member] | Grant Date Value Of Stock Awards In Fiscal Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (289,006) | (400,405) | (319,391) |
| Non-PEO NEO [Member] | Changes In Fair Value Of Outstanding And Unvested Stock Awards Granted In Prior Year And Fiscal Year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | $ 477,747 | $ 1,373,946 | $ 560,709 |
