Fair Value Measurements - Assets and Liabilities Not Measured and Reported at Fair Value on a Recurring Basis or Nonrecurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Financial assets
Securities held to maturity	$ 1,003,497	$ 1,002,544
Securities available for sale	1,002,056	831,013
Loans held for sale	226,003	246,171
Mortgage servicing rights	72,902	72,991
Derivative instruments	26,825	34,505
Financial liabilities
Derivative instruments	22,917	28,550
Carrying Value
Financial assets
Cash and cash equivalents	1,091,339	1,092,032
Securities held to maturity	1,101,901	1,126,112
Securities available for sale	1,002,056	831,013
Loans held for sale	226,003	246,171
Loans, net	12,851,662	12,683,264
Mortgage servicing rights	72,902	72,991
Derivative instruments	37,562	38,954
Financial liabilities
Deposits	14,772,095	14,572,612
Short-term borrowings	108,015	108,018
Junior subordinated debentures	114,150	113,916
Subordinated notes	319,159	316,698
Derivative instruments	31,477	32,268
Fair Value
Financial assets
Cash and cash equivalents	1,091,339	1,092,032
Securities held to maturity	1,003,497	1,002,544
Securities available for sale	1,002,056	831,013
Loans held for sale	226,003	246,171
Loans, net	12,595,656	12,340,638
Mortgage servicing rights	93,372	96,290
Derivative instruments	37,562	38,954
Financial liabilities
Deposits	14,764,246	14,570,304
Short-term borrowings	108,015	108,018
Junior subordinated debentures	101,251	100,668
Subordinated notes	306,888	295,868
Derivative instruments	31,477	32,268
Fair Value | Level 1
Financial assets
Cash and cash equivalents	1,091,339	1,092,032
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	12,308,196	12,093,327
Short-term borrowings	108,015	108,018
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	1,003,497	1,002,544
Securities available for sale	1,002,056	831,013
Loans held for sale	226,003	246,171
Loans, net	0	0
Mortgage servicing rights	0	0
Derivative instruments	37,562	38,954
Financial liabilities
Deposits	2,456,050	2,476,977
Short-term borrowings	0	0
Junior subordinated debentures	101,251	100,668
Subordinated notes	306,888	295,868
Derivative instruments	31,477	32,268
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	12,595,656	12,340,638
Mortgage servicing rights	93,372	96,290
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