Fair Value Measurements - Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Mortgage servicing rights	$ 81,036	$ 78,390	$ 74,097	$ 73,850	$ 66,047	$ 47,392
Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale securities	495,992		536,973
Loans held-for-sale	51,465		57,323
Mortgage servicing rights	81,036		74,097
Derivative financial instruments - assets	50,815		40,287
Derivative financial instruments - liabilities	(31,593)		(24,527)
Total	647,715		684,153
Fair Value, Recurring | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale securities	52,853		56,649
Loans held-for-sale	0		0
Mortgage servicing rights	0		0
Derivative financial instruments - assets	0		0
Derivative financial instruments - liabilities	0		0
Total	52,853		56,649
Fair Value, Recurring | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale securities	443,139		480,324
Loans held-for-sale	51,465		57,323
Mortgage servicing rights	0		0
Derivative financial instruments - assets	50,815		40,287
Derivative financial instruments - liabilities	(31,593)		(24,527)
Total	513,826		553,407
Fair Value, Recurring | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale securities	0		0
Loans held-for-sale	0		0
Mortgage servicing rights	81,036		74,097
Derivative financial instruments - assets	0		0
Derivative financial instruments - liabilities	0		0
Total	$ 81,036		$ 74,097