Fair Value Measurements - Segregated by Level of Valuation Inputs (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financial assets:
Fair Value	$ 942,846
Debt securities held to maturity	942,846
Portfolio loans, net	7,184,660	$ 7,101,111
Financial liabilities:
Short-term borrowings	17,683	17,678
Junior subordinated debt owed to unconsolidated trusts	71,678	71,635
Level 1 | Carrying Amount
Financial assets:
Cash and cash equivalents	479,228	836,095
Level 1 | Fair Value
Financial assets:
Cash and cash equivalents	479,228	836,095
Level 2 | Carrying Amount
Financial assets:
Fair Value	976,081
Debt securities held to maturity	976,081
Loans held for sale	6,765
Accrued interest receivable	31,947	31,064
Financial liabilities:
Time deposits	890,830	935,649
Securities sold under agreements to repurchase	255,668	270,139
Short-term borrowings	17,683	17,678
Long-term debt	42,881	46,056
Junior subordinated debt owed to unconsolidated trusts	71,678	71,635
Accrued interest payable	5,116	2,728
Level 2 | Fair Value
Financial assets:
Fair Value	942,846
Debt securities held to maturity	942,846
Loans held for sale	6,769
Accrued interest receivable	31,947	31,064
Financial liabilities:
Time deposits	882,358	935,778
Securities sold under agreements to repurchase	255,668	270,139
Short-term borrowings	17,745	17,673
Long-term debt	43,007	46,164
Junior subordinated debt owed to unconsolidated trusts	62,840	63,586
Accrued interest payable	5,116	2,728
Level 3 | Carrying Amount
Financial assets:
Portfolio loans, net	7,184,660	7,101,111
Mortgage servicing rights	8,085	8,608
Other servicing rights	1,712	1,830
Level 3 | Fair Value
Financial assets:
Portfolio loans, net	7,195,985	7,161,466
Mortgage servicing rights	15,499	12,133
Other servicing rights	2,093	2,268
Level 3 | Senior notes | Carrying Amount
Financial liabilities:
Long-term debt	39,978	39,944
Level 3 | Senior notes | Fair Value
Financial liabilities:
Long-term debt	40,000	40,400
Level 3 | Subordinated debt | Carrying Amount
Financial liabilities:
Long-term debt	182,910	182,773
Level 3 | Subordinated debt | Fair Value
Financial liabilities:
Long-term debt	$ 188,437	$ 195,600