SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) segment shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares
Cash and Cash Equivalents
Restricted cash	$ 0	$ 43,000
Other Investments
Interest receivable	7,700	2,400
Debt securities held-to-maturity, at amortized cost, net of allowance for credit losses of $— and $— (fair value of $114,538 and $78,206)	134,864	79,850
Held-to-maturity securities	0	0
Other investments	110,992	47,552
Allowance for Credit Losses
Interest receivable	7,700	2,400
Deferred interest on financing receivable allowance for credit losses	$ 0	214
Leases
Initial lease terms	13 years
Share-based Compensation
Company stock-based compensation cost	$ 6,700	$ 7,900	$ 3,900
Earnings Per Share
Anti-dilutive common shares excluded (in shares) | shares	0	0	197,765
Operating Segments
Number of reportable segments | segment	5
Minimum | Core deposit premiums
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	7 years
Maximum | Core deposit premiums
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	10 years
Financing receivable
Other Investments
Interest receivable	$ 69,300	$ 54,800
Allowance for Credit Losses
Interest receivable	$ 69,300	$ 54,800
Buildings and leasehold improvements | Maximum
Premises and Equipment
Estimated useful lives, premises and equipment	40 years
Furniture and equipment | Minimum
Premises and Equipment
Estimated useful lives, premises and equipment	3 years
Furniture and equipment | Maximum
Premises and Equipment
Estimated useful lives, premises and equipment	20 years
Software And Computer Equipment | Minimum
Premises and Equipment
Estimated useful lives, premises and equipment	3 years
Software And Computer Equipment | Maximum
Premises and Equipment
Estimated useful lives, premises and equipment	5 years
US Premium Financing Holding Company | Minimum | Referral relationships
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	8 years
US Premium Financing Holding Company | Minimum | Trade names
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	5 years
US Premium Financing Holding Company | Minimum | Non-compete agreements
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	3 years
US Premium Financing Holding Company | Maximum | Referral relationships
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	10 years
US Premium Financing Holding Company | Maximum | Trade names
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	7 years
US Premium Financing Holding Company | Maximum | Non-compete agreements
Goodwill and Intangible Assets
Acquired finite-lived intangible assets, weighted average useful life	10 years
Visa Class B Shares
Other Investments
Shares held in other investment (in shares) | shares	57,611
Other investments	$ 242
Conversation ratio	1.5991