Fair Value Measurements - Assets and Liabilities Not Measured and Reported at Fair Value on a Recurring Basis or Nonrecurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financial assets
Securities held to maturity	$ 1,153,541	$ 1,206,540
Securities available for sale	950,930	1,533,942
Loans held for sale	249,615	110,105
Mortgage servicing rights	87,432	84,448
Derivative instruments	36,832	36,493
Financial liabilities
Derivative instruments	23,894	22,056
Carrying Value
Financial assets
Cash and cash equivalents	946,899	575,992
Securities held to maturity	1,273,044	1,324,040
Securities available for sale	950,930	1,533,942
Loans held for sale	249,615	110,105
Loans, net	11,736,125	11,386,214
Mortgage servicing rights	87,432	84,448
Derivative instruments	38,746	38,047
Financial liabilities
Deposits	14,095,361	13,486,966
Short-term borrowings	257,305	712,232
Junior subordinated debentures	112,510	112,042
Subordinated notes	317,120	316,091
Derivative instruments	35,151	33,185
Fair Value
Financial assets
Cash and cash equivalents	946,899	575,992
Securities held to maturity	1,153,541	1,206,540
Securities available for sale	950,930	1,533,942
Loans held for sale	249,615	110,105
Loans, net	11,059,520	10,850,181
Mortgage servicing rights	125,055	122,454
Derivative instruments	38,746	38,047
Financial liabilities
Deposits	14,057,773	13,445,417
Short-term borrowings	257,305	712,232
Junior subordinated debentures	93,243	98,754
Subordinated notes	258,250	277,500
Derivative instruments	35,151	33,185
Fair Value | Level 1
Financial assets
Cash and cash equivalents	946,899	575,992
Securities held to maturity	0	0
Securities available for sale	0	0
Loans held for sale	0	0
Loans, net	0	0
Mortgage servicing rights	0	0
Derivative instruments	0	0
Financial liabilities
Deposits	11,139,951	11,791,526
Short-term borrowings	257,305	712,232
Junior subordinated debentures	0	0
Subordinated notes	0	0
Derivative instruments	0	0
Fair Value | Level 2
Financial assets
Cash and cash equivalents	0	0
Securities held to maturity	1,153,541	1,206,540
Securities available for sale	950,930	1,533,942
Loans held for sale	249,615	110,105
Loans, net	0	0
Mortgage servicing rights	0	0
Derivative instruments	38,746	38,047
Financial liabilities
Deposits	2,917,822	1,653,891
Short-term borrowings	0	0
Junior subordinated debentures	93,243	98,754
Subordinated notes	258,250	277,500
Derivative instruments	35,151	33,185
Fair Value | Level 3
Financial assets
Cash and cash equivalents	0	0
Securities held to maturity	0	0
Securities available for sale	0	0
Loans held for sale	0	0
Loans, net	11,059,520	10,850,181
Mortgage servicing rights	125,055	122,454
Derivative instruments	0	0
Financial liabilities
Deposits	0	0
Short-term borrowings	0	0
Junior subordinated debentures	0	0
Subordinated notes	0	0
Derivative instruments	$ 0	$ 0