Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 218,277	$ 204,572	$ 111,515
Adjustments to reconcile net income to net cash from operating activities:
Discount accretion, net of depreciation and amortization	20,087	26,000	12,244
Stock-based compensation expense	12,263	8,398	8,127
Provision (credit) for credit losses	9,600	(12,200)	95,000
Provision (credit) for unfunded loan commitments	250	(195)	660
Provision for accrued interest receivables on loans	1,107	846	1,000
Valuation adjustment of OREO	415	1,621	3,284
Write-down of right-of-use assets	0	0	1,751
Net gains on sales of SBA loans	(17,418)	(12,883)	(8,004)
Net losses on sales of OREO	(178)	(684)	(108)
Net gains on sales and calls of securities available for sale	0	0	(7,531)
Net change in fair value of equity investments with readily determinable fair value	1,912	789	(488)
Losses on investments in affordable housing partnerships	10,374	10,774	12,863
Payment of FHLB prepayment fee	0	0	3,584
Software impairment	0	2,146	0
Net change in deferred income taxes	(8,955)	19,626	(17,998)
Proceeds from sales of loans held for sale	238,904	229,302	305,060
Originations of loans held for sale	(55,466)	(192,161)	(268,283)
Originations of servicing assets	(5,200)	(2,880)	(2,864)
Net change in accrued interest receivable	(17,248)	16,742	(28,658)
Net change in other assets	(3,519)	49,010	(59,228)
Net change in accrued interest payable	22,396	(10,434)	(19,104)
Net change in other liabilities	57,578	(15,546)	22,878
Net cash provided by operating activities	485,535	324,211	165,916
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of interest bearing deposits in other financial institutions	0	(4,233)	(20,597)
Redemption of interest bearing deposits in other financial institutions	12,116	20,024	21,117
Purchase of securities	(212,496)	(1,159,057)	(1,273,369)
Proceeds from matured, called, or paid-down securities	324,706	694,715	565,362
Proceeds from sale of securities	0	0	168,069
Purchase of securities	(41,583)	0	0
Proceeds from matured, called, or paid-down securities	11,638	0	0
Proceeds from sales of equity investments	20,603	1,277	201
Purchase of equity investments	(350)	0	(10,000)
Proceeds from sales of other loans held for sale previously classified as held for investment	160,805	335,888	1,294
Purchase of loans receivable	(56,266)	(214,988)	0
Net change in loans receivable	(1,680,144)	(671,581)	(1,273,988)
Proceeds from sales of OREO	524	15,220	2,458
Purchase of FHLB stock	(21,378)	0	(1,346)
Redemption of FHLB stock	19,998	0	3,503
Purchase of premises and equipment	(9,111)	(7,220)	(4,973)
Proceeds from BOLI death benefits	1,215	1,283	970
Investments in affordable housing partnerships	(3,903)	(4,368)	(13,333)
Net cash used in investing activities	(1,473,626)	(993,040)	(1,834,632)
CASH FLOWS FROM FINANCING ACTIVITIES
Net change in deposits	698,351	706,538	1,806,548
Proceeds from FHLB advances	23,750,885	2,319,000	1,360,000
Repayment of FHLB advances	(23,450,885)	(2,269,000)	(1,738,584)
Proceeds from FRB borrowings	16,548,000	0	0
Repayment of FRB borrowings	(16,283,000)	0	0
Purchase of treasury stock	(14,667)	(50,000)	(36,777)
Cash dividends paid on common stock	(67,126)	(68,666)	(69,182)
Taxes paid in net settlement of restricted stock	(3,488)	(3,356)	(1,277)
Issuance of additional stock pursuant to various stock plans	531	0	0
Net cash provided by financing activities	1,178,601	634,516	1,320,728
NET CHANGE IN CASH AND CASH EQUIVALENTS	190,510	(34,313)	(347,988)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	316,266	350,579	698,567
CASH AND CASH EQUIVALENTS, END OF PERIOD	506,776	316,266	350,579
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest paid	113,148	62,081	144,234
Income taxes paid	96,398	42,201	49,220
SUPPLEMENTAL DISCLOSURES OF NON-CASH ACTIVITIES
Transfer from loans receivable to OREO	938	0	2,928
Transfer from loans receivable to loans held for sale	311,535	472,598	1,243
Transfer from loans held for sale to loans receivable	12,021	19,625	2,933
Transfer from investment securities available for sale to held to maturity, at fair value	238,966	0	0
Lease liabilities arising from obtaining right-of-use assets	$ 16,977	$ 965	$ 0