Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Cash Flows from Operating Activities
Net income	$ 75,028	$ 73,384
Adjustments to reconcile net income to net cash provided by operating activities:
Provision/(reversal) for credit losses	8,643	(13,558)
Deferred tax provision	3,118	6,135
Depreciation and amortization	2,112	2,044
Amortization of right-of-use asset	2,443	2,221
Change in operating lease liabilities	(1,744)	2,319
Net gains on sale and transfer of other real estate owned	(6)	0
Net gains on sale of loans	0	(289)
Proceeds from sales of loans	0	6,345
Originations of loans held for sale	0	(6,056)
Loss on sales or disposal of fixed assets	25	22
Amortization on alternative energy partnerships, venture capital and other investments	8,287	11,641
Net gain on sales and calls of securities	100	(853)
Amortization/accretion of security premiums/discounts, net	1,494	2,282
Unrealized (gain)/loss on equity securities	(5,874)	2,752
Stock-based compensation and stock issued to officers as compensation	1,614	1,243
Net change in accrued interest receivable and other assets	(13,309)	11,863
Net change in other liabilities	4,726	(9,924)
Net cash provided by operating activities	86,457	91,571
Cash Flows from Investing Activities
Purchase of investment securities available-for-sale	(204,882)	(50,450)
Proceeds from repayments, maturities and calls of investment securities available-for-sale	45,393	148,685
Proceeds from sale of investment securities available-for-sale	553	21,102
Net increase in loans	(413,721)	(15,246)
Purchase of premises and equipment	(1,276)	(760)
Proceeds from sales of other real estate owned	307	0
Net decrease/(increase) in investment in affordable housing and alternative energy partnerships	902	(5,950)
Acquisition, net of cash acquired	(73,882)	0
Net cash (used)/provided for investing activities	(646,606)	97,381
Cash Flows from Financing Activities
Net (decrease)/increase in deposits	(573,720)	244,327
Advances from Federal Home Loan Bank	0	50,000
Repayment of Federal Home Loan Bank borrowings	0	(125,000)
Cash dividends paid	(25,515)	(24,650)
Purchases of treasury stock	(32,896)	0
Proceeds from shares issued under Dividend Reinvestment Plan	945	868
Taxes paid related to net share settlement of RSUs	(285)	(1,279)
Net cash (used)/provided by financing activities	(631,471)	144,266
(Decrease)/Increase in cash, cash equivalents, and restricted cash	(1,191,620)	333,218
Cash, cash equivalents, and restricted cash, beginning of the period	2,449,704	1,421,078	$ 1,421,078
Cash, cash equivalents, and restricted cash, end of the period	1,258,084	1,754,296	$ 2,449,704
Supplemental disclosure of cash flow information
Interest	12,896	25,872
Income taxes paid	1,281	2,891
Non-cash investing and financing activities:
Net change in unrealized holding loss on securities available-for-sale, net of tax	(45,966)	(4,887)
Net change in unrealized holding gain on cash flow hedge derivatives	3,054	1,263
Transfers to other real estate owned from loans held for investment	$ 0	$ 0