Fair Value - Carrying Amounts and Estimated Fair Values of Company's Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financial Assets:
Interest Bearing Time Deposits with Banks	$ 995	$ 745
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,829,610)	(4,744,316)
Time Deposits	(512,884)	(347,099)
Carrying Value
Financial Assets:
Cash and Short-term Investments	670,592	396,890
Interest Bearing Time Deposits with Banks	995	745
Loans, Net	3,577,516	2,960,728
Accrued Interest Receivable	22,892	20,229
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,316,726)	(4,397,217)
Time Deposits	(512,884)	(347,099)
Short-term Borrowings	(53,736)	(68,328)
Long-term Debt	(102,388)	(83,855)
Accrued Interest Payable	(1,319)	(613)
Estimate of Fair Value Measurement
Financial Assets:
Cash and Short-term Investments	670,592	396,890
Interest Bearing Time Deposits with Banks	995	745
Loans, Net	3,570,214	2,980,555
Accrued Interest Receivable	22,892	20,229
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,316,726)	(4,397,217)
Time Deposits	(514,394)	(347,876)
Short-term Borrowings	(53,736)	(68,328)
Long-term Debt	(101,547)	(86,623)
Accrued Interest Payable	(1,319)	(613)
Estimate of Fair Value Measurement | Level 1
Financial Assets:
Cash and Short-term Investments	60,477	47,173
Interest Bearing Time Deposits with Banks	0	0
Loans, Net	0	0
Accrued Interest Receivable	0	0
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(5,316,726)	(4,397,217)
Time Deposits	0	0
Short-term Borrowings	0	0
Long-term Debt	0	0
Accrued Interest Payable	0	0
Estimate of Fair Value Measurement | Level 2
Financial Assets:
Cash and Short-term Investments	610,115	349,717
Interest Bearing Time Deposits with Banks	995	745
Loans, Net	0	0
Accrued Interest Receivable	10,513	9,213
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	(514,394)	(347,876)
Short-term Borrowings	(53,736)	(68,328)
Long-term Debt	(27,527)	(28,320)
Accrued Interest Payable	(1,301)	(579)
Estimate of Fair Value Measurement | Level 3
Financial Assets:
Cash and Short-term Investments	0	0
Interest Bearing Time Deposits with Banks	0	0
Loans, Net	3,570,214	2,980,555
Accrued Interest Receivable	12,379	11,016
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	0	0
Short-term Borrowings	0	0
Long-term Debt	(74,020)	(58,303)
Accrued Interest Payable	$ (18)	$ (34)