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Other Borrowed Funds (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 2,494,428 |  | $ 3,821,361 | $ 8,621,328
Average Balance |  | $ 5,062,621 |  | $ 8,570,959 | $ 10,261,592
Rate |  | 0.56% |  | 0.82% | 2.37%
Other borrowed funds, Maturities [Abstract] |  |  |  |  |
2022 |  | $ 2,343,341 |  |  |
2023 |  | 3,378 |  |  |
2024 |  | 3,498 |  |  |
2025 |  | 3,622 |  |  |
2026 |  | 3,752 |  |  |
Thereafter |  | 136,837 |  |  |
Funds purchased [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 199,513 |  | $ 769,365 | $ 3,390,528
Rate |  | 0.05% |  | 0.05% | 1.53%
Average Balance |  | $ 543,183 |  | $ 2,045,795 | $ 2,438,376
Rate |  | 0.46% |  | 0.58% | 2.08%
Maximum Outstanding At Any Month End |  | $ 542,465 |  | $ 3,311,938 | $ 3,390,528
Repurchase agreements [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 2,126,936 |  | $ 893,021 | $ 427,822
Rate |  | 0.08% |  | 0.09% | 0.50%
Average Balance |  | $ 1,695,519 |  | $ 1,589,746 | $ 399,785
Rate |  | 0.33% |  | 0.24% | 0.57%
Maximum Outstanding At Any Month End |  | $ 2,920,728 |  | $ 3,230,097 | $ 427,822
Other Borrowings [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | 36,753 |  | 1,882,970 | 4,527,055
Average Balance |  | $ 2,599,861 |  | $ 4,659,453 | $ 7,147,356
Rate |  | 0.38% |  | 0.88% | 2.45%
Federal Home Loan Bank advances [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 0 |  | $ 200,000 | $ 4,500,000
Rate |  | 0.00% |  | 0.29% | 1.79%
Average Balance |  | $ 1,679,315 |  | $ 3,393,989 | $ 7,122,466
Rate |  | 0.27% |  | 1.00% | 2.44%
Maximum Outstanding At Any Month End |  | $ 2,600,000 |  | $ 7,500,000 | $ 8,000,000
GNMA repurchase liability [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 7,420 |  | $ 19,500 | $ 15,417
Rate |  | 4.36% |  | 4.35% | 4.32%
Average Balance |  | $ 11,956 |  | $ 42,771 | $ 13,746
Rate |  | 4.06% |  | 4.18% | 4.47%
Maximum Outstanding At Any Month End |  | $ 23,856 |  | $ 126,569 | $ 19,581
Federal Reserve Bank Advances |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  |  |  | $ 0 |
Rate |  |  |  | 0.00% |
Average Balance |  |  |  | $ 42,464 |
Rate |  |  |  | 0.26% |
Maximum Outstanding At Any Month End |  |  |  | $ 0 |
Paycheck protection program liquidity facility |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 0 |  | $ 1,635,963 |
Rate |  | 0.00% |  | 0.35% |
Average Balance |  | $ 879,145 |  | $ 1,152,073 |
Rate |  | 0.35% |  | 0.35% |
Maximum Outstanding At Any Month End |  | $ 1,662,598 |  | $ 2,013,414 |
Other [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 29,333 |  | $ 27,507 | $ 11,638
Rate |  | 3.23% |  | 5.24% | 5.09%
Average Balance |  | $ 29,445 |  | $ 28,156 | $ 11,144
Rate |  | 4.18% |  | 5.12% | 5.30%
Maximum Outstanding At Any Month End |  | $ 31,875 |  | $ 49,376 | $ 34,676
Subordinated debentures [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance | [1] | $ 131,226 |  | $ 276,005 | $ 275,923
Rate | [1] | 3.95% |  | 4.72% | 5.15%
Average Balance | [1] | $ 224,058 |  | $ 275,965 | $ 276,075
Rate | [1] | 4.70% |  | 5.05% | 5.47%
Maximum Outstanding At Any Month End | [1] | $ 276,049 |  | $ 276,005 | $ 275,923
Subordinated debentures [Member] | Subordinated debentures, 2016 issuance [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Amount of debt issuance |  | $ 150,000 |  |  |
Maturity date |  | Jun. 30, 2056 |  |  |
Stated interest rate |  | 5.375% |  |  |
Gain (Loss) on Extinguishment of Debt |  | $ 5,200 |  |  |
Subordinated debentures [Member] | Subordinated debentures-acquired, 2015 Issuance [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Amount of debt issuance |  | $ 60,000 |  |  |
Maturity date |  | Jun. 25, 2030 |  |  |
Interest rate description |  | three-month LIBOR plus 3.17% |  |  |
Stated interest rate |  | 5.625% |  |  |
Debt Instrument, Call Date, Earliest |  | Jun. 25, 2025 |  |  |
Subordinated debentures [Member] | Junior subordinated debentures-acquired, 2003 issuance [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Amount of debt issuance |  | $ 21,000 |  |  |
Maturity date |  | Sep. 17, 2033 |  |  |
Interest rate description |  | three-month LIBOR plus 2.95% |  |  |
Subordinated debentures [Member] | Junior subordinated debentures-acquired, 2004 issuance [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Amount of debt issuance |  | $ 31,000 |  |  |
Maturity date |  | Jul. 23, 2034 |  |  |
Interest rate description |  | three-month LIBOR plus 2.60% |  |  |
Subordinated debentures [Member] | Junior subordinated debentures-acquired, 2005 issuance [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Amount of debt issuance |  | $ 20,000 |  |  |
Maturity date |  | Sep. 30, 2035 |  |  |
Interest rate description |  | three-month LIBOR plus 1.45% |  |  |
U.S. government agency mortgage-backed securities [Member] |  |  |  |  |
Assets Sold under Agreements to Repurchase [Line Items] |  |  |  |  |
Amortized Cost |  | $ 907,154 |  | 893,069 |
Fair Value |  | 2,144,507 |  | 910,885 |
Repurchase Liability | [2] | $ 2,126,936 |  | $ 893,021 |
Average Rate (in hundredths) |  | 1.58% |  | 0.09% |
U.S. government agency mortgage-backed securities [Member] | Overnight [Member] |  |  |  |  |
Assets Sold under Agreements to Repurchase [Line Items] |  |  |  |  |
Amortized Cost |  | $ 907,154 |  | $ 893,069 |
Fair Value |  | 902,507 |  | 910,885 |
Repurchase Liability | [2] | $ 884,936 |  | $ 893,021 |
Average Rate (in hundredths) |  | 0.08% |  | 0.09% |
U.S. government agency mortgage-backed securities [Member] | Less than 30 Days |  |  |  |  |
Assets Sold under Agreements to Repurchase [Line Items] |  |  |  |  |
Amortized Cost |  |  |  | $ 0 |
Fair Value |  | $ 1,242,000 | [3] | 0 |
Repurchase Liability | [2] | $ 1,242,000 | [3] | $ 0 |
Average Rate (in hundredths) |  | 1.50% | [3] | 0.00% |
Subsidiaries [Member] | Funds purchased [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Number of days to maturity, minimum |  | 1 day |  |  |
Number of days to maturity, maximum |  | 90 days |  |  |
Subsidiaries [Member] | Repurchase agreements [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Number of days to maturity, maximum |  | 90 days |  |  |
Subsidiaries [Member] | Federal Home Loan Bank advances [Member] |  |  |  |  |
Other borrowed funds, Other Disclosures [Abstract] |  |  |  |  |
Federal Home Loan Banks, Letters of credit issued to secure public funds |  | $ 500,000 |  |  |
Unused credit available pursuant to the FHLB's collateral policies |  | 5,900,000 |  |  |
Subsidiaries [Member] | BOK Financial Securities, Inc. [Member] | Other [Member] |  |  |  |  |
Other Borrowed Funds [Line Items] |  |  |  |  |
Balance |  | $ 0 |  | $ 0 |
[1] | Parent Company only.
[2] | BOK Financial maintains control over the securities underlying overnight repurchase agreements and generally transfers control over securities underlying longer-term dealer repurchase agreements to the respective counterparty.
[3] | Trading position.

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