CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021
OPERATING ACTIVITIES:
Net income	$ 43,963,000	$ 49,927,000	$ 54,382,000	$ 46,855,000
Adjustments to reconcile net income to net cash provided from operating activities:
Depreciation	4,169,000			4,411,000
Deferred income/expense, net of amortization	(1,838,000)			(7,048,000)
Amortization of core deposit intangibles	(739,000)			(155,000)
Gain on sale of securities, net	(435,000)			(485,000)
Net change in valuation of financial instruments carried at fair value	(49,000)			(59,000)
Increase in deferred taxes	(860,000)			(281,000)
Increase in current taxes payable	7,595,000			9,506,000
Stock-based compensation	2,081,000			2,152,000
Net change in cash surrender value of BOLI	(1,519,000)			(1,002,000)
Gain on sale of loans, excluding capitalized servicing rights	(1,909,000)			(9,487,000)
Loss (gain) on disposal of real estate held for sale and property and equipment, net	109,000			(298,000)
Recapture of provision for credit losses	(6,961,000)			(9,251,000)
Loss on extinguishment of debt	765,000			0
Origination of loans held for sale	(208,270,000)			(301,393,000)
Proceeds from sales of loans held for sale	226,074,000			419,412,000
Net change in:
Other assets	(10,245,000)			2,602,000
Other liabilities	(4,421,000)			164,729,000
Net cash provided from operating activities	50,654,000			322,481,000
INVESTING ACTIVITIES:
Purchases of securities—available-for-sale	281,353,000			1,225,723,000
Principal repayments and maturities of securities—available-for-sale	106,937,000			434,651,000
Proceeds from sales of securities—available-for-sale	12,767,000			48,784,000
Purchases of securities—held-to-maturity	(40,351,000)			(31,170,000)
Principal repayments and maturities of securities—held-to-maturity	7,573,000			9,982,000
Purchases of equity securities	0			(4,750,000)
Proceeds from sales of equity securities	0			4,796,000
Loan repayments (originations), net	31,355,000			(77,834,000)
Purchases of loans and participating interest in loans	(75,575,000)			0
Proceeds from sales of other loans	5,034,000			8,367,000
Purchases of property and equipment	(3,306,000)			(2,334,000)
Proceeds from sale of real estate held for sale and sale of other property	5,616,000			1,999,000
Proceeds from FHLB stock repurchase program	2,000,000			2,358,000
Investment in bank-owned life insurance	(50,040,000)			(3,000)
Other	1,098,000			1,421,000
Net cash used by investing activities	(278,245,000)			(829,456,000)
FINANCING ACTIVITIES:
Increase in deposits, net	196,841,000			981,571,000
Repayment of long term FHLB advances	50,000,000			50,000,000
Increase in other borrowings, net	2,288,000			31,474,000
Repayment of junior subordinated debentures	(50,518,000)			0
Proceeds from redemption of trust securities related to junior subordinated debentures	1,518,000			0
Cash dividends paid	(15,200,000)			(14,565,000)
Cash paid for repurchase of common stock	0			25,324,000
Taxes paid related to net share settlement of equity awards	3,250,000			437,000
Net Cash Provided by (Used in) Financing Activities, Total	81,679,000			922,719,000
NET CHANGE IN CASH AND CASH EQUIVALENTS	(145,912,000)			415,744,000
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	2,134,300,000		$ 1,649,927,000	1,234,183,000
CASH AND CASH EQUIVALENTS, END OF PERIOD	1,988,388,000	$ 2,134,300,000		1,649,927,000
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid in cash	3,526,000			5,829,000
Tax paid	120,000			100,000
NON-CASH INVESTING AND FINANCING TRANSACTIONS:
Dividends Payable	1,204,000			1,381,000
Loans, held-for-sale, transferred to portfolio	13,420,000			0
Securities, available-for-sale, transferred to held-to-maturity	462,159,000			0
Amortization of core deposit intangibles	$ 1,424,000			$ 1,711,000