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Acquisitions - Schedule of Recognized Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands | Feb. 01, 2022 | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | --- | ---
Liabilities assumed: |  |  |
Goodwill |  | $ 1,100,900 | $ 1,100,900
Great Western Bank |  |  |
Assets acquired: |  |  |
Cash and cash equivalents | $ 2,006,900 |  |
Investment securities | 2,699,000 |  |
Securities purchased under agreement to resell | 101,100 |  |
Loans held for sale | 217,000 |  |
Loans held for investment | 7,705,000 |  |
Allowance for credit losses | (59,500) |  |
Premises and equipment, including right of use lease assets | 144,700 |  |
OREO | 15,800 |  |
Company-owned life insurance | 186,600 |  |
Core deposit intangibles | 50,100 |  |
Customer relationship intangible | 22,800 |  |
Mortgage servicing rights | 1,300 |  |
Deferred tax assets, net | 60,200 |  |
Other assets | 200,800 |  |
Total assets acquired | 13,351,800 |  |
Liabilities assumed: |  |  |
Deposits | 11,688,000 |  |
Securities sold under repurchase agreements | 74,000 |  |
Accrued expenses and other liabilities | 110,400 |  |
FHLB advances | 122,900 |  |
Subordinated debt | 36,400 |  |
Subordinated debentures held by subsidiary trusts | 76,100 |  |
Total liabilities assumed | 12,107,800 |  |
Net assets acquired | 1,244,000 |  |
Class A common stock | 1,723,300 |  |
Total consideration paid (1) | 1,723,300 |  |
Goodwill | 479,300 |  |
Cash paid in lieu of fractional shares | $ 13 |  |

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