Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash Flows from Operating Activities
Net income	$ 315,124	$ 285,979	$ 354,124
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	72,631	37,500	25,978
Provision for losses on other real estate owned	1,752	1,164	0
Deferred tax provision/(benefit)	12,145	(20,756)	(4,782)
Depreciation and amortization	6,598	7,183	8,371
Amortization of right-of-use asset	9,438	9,646	9,733
Change in operating lease liabilities	5,251	(3,946)	2,279
Net gains on sale and transfers of other real estate owned	(3,898)	0	0
Net (gains)/losses on sale of loans	(435)	737	0
Loss on sales or disposal of fixed assets	63	0	6
Amortization of alternative energy partnerships, venture capital and other investments	43,614	72,633	86,616
Net gain on sales and calls of securities	0	(1,107)	0
Amortization/accretion of security premiums/discount, net	(27,043)	(25,369)	(11,373)
Unrealized (gain)/loss on equity securities	(7,392)	7,516	(18,248)
Write-off of AFS debt securities	0	0	3,000
Stock-based compensation and stock issued to officers as compensation	7,610	6,804	7,836
Net change in accrued interest receivable and other assets	26,722	(10,050)	(54,369)
Net change in other liabilities	(93,611)	(38,779)	(24,429)
Net cash provided by operating activities	368,569	329,155	384,742
Cash Flows from Investing Activities
Purchase of investment securities available-for-sale	(1,712,903)	(1,358,614)	(618,334)
Purchase of equity securities	(3,000)	0	0
Proceeds from repayment, maturity, and call of investment securities available-for-sale	1,673,156	1,407,915	522,815
Proceeds from sale of investment securities available-for-sale	0	33,690	0
Purchase of Federal Home Loan Bank stock	0	(12,535)	(29,381)
Redemption of Federal Home Loan Bank stock	0	13,031	28,885
Proceeds from sale of loans originally classified as held-for-investment	50,329	172,960	0
Net increase in loans	(876,884)	(36,018)	(1,327,048)
Purchase of premises and equipment	(4,911)	(3,636)	(3,401)
Proceeds from sales of other real estate owned	14,038	0	0
Net increase/(decrease) in investment in affordable housing and alternative energy partnerships	2,854	(32,763)	(50,616)
Net cash (used)/provided for investing activities	(857,321)	184,030	(1,477,080)
Cash Flows from Financing Activities
Increase in deposits	1,207,898	360,997	820,041
Advances from Federal Home Loan Bank	11,348,000	6,968,000	14,035,000
Repayment of Federal Home Loan Bank borrowings	(11,408,000)	(7,448,000)	(13,980,000)
Cash dividends paid	(93,800)	(97,967)	(98,638)
Purchase of treasury stock	(180,288)	(84,703)	(16,667)
Proceeds from shares issued under Dividend Reinvestment Plan	2,610	2,933	3,491
Taxes paid related to net share settlement of RSUs	(2,779)	(3,726)	(4,490)
Net cash provided/(used) by financing activities	873,641	(302,466)	758,737
Increase/(decrease) in cash, cash equivalents, and restricted cash	384,889	210,719	(333,601)
Cash, cash equivalents, and restricted cash, beginning of the year	1,039,520	828,801	1,162,402
Cash, cash equivalents, and restricted cash, end of the period	1,424,409	1,039,520	828,801
Supplemental Cash Flow Information
Interest	568,674	662,066	484,861
Income taxes	55,816	56,172	70,332
Non-cash investing and financing activities:
Net change in unrealized holding gain/(loss) on securities available-for-sale, net of tax	31,207	583	18,642
Net (loss)/gain (1)	0	(774)	(1,763)
Loans transferred from held-for-investment to held-for-sale	58,832	173,697	0
Transfers to other real estate owned from loans held-for-investment	11,357	4,794	15,374
Transfers to other real estate owned from loans held-for-sale	$ 8,938	$ 0	$ 0