Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows From Operating Activities
Net income	$ 159,909	$ 95,944
Adjustments to reconcile net income to net cash provided by operating activities
Provision (recapture) for credit losses	(6,300)	82,400
Stock-based compensation expense	10,835	7,918
Depreciation, amortization and accretion	11,383	14,456
Investment securities gain, net	314	16,674
Net realized gain on sale of premises and equipment, loans held for investment and OPPO	268	953
Net realized (gain) loss on sale and valuation adjustments of OREO	(40)	64
Gain on bank owned life insurance death benefit	209	0
Originations of loans held for sale	263,367	356,962
Proceeds from sales of loans held for sale	278,187	350,273
Change in fair value of loans held for sale	306	0
Net change in:
Interest receivable	1,945	(9,879)
Interest payable	(52)	(399)
Other assets	15,761	(53,996)
Other liabilities	(18,755)	31,703
Net cash provided by operating activities	189,101	143,767
Cash Flows From Investing Activities
Loans originated, net of principal collected	108,551	(938,624)
Investment in low income housing tax credit partnerships	(1,106)	0
Purchases of Debt Securities, Available-for-sale	2,408,578	996,951
Purchases of debt securities held to maturity	(112,372)	0
Purchases of loans held for investment	176,545	0
Purchases of premises and equipment	(4,334)	(7,538)
Purchases of FHLB stock	(1)	(53,240)
Proceeds from sale of debt securities, available-for-sale	26,914	194,105
Proceeds from sale of equity securities	0	3,000
Proceeds from principal repayments and maturities of debt securities available for sale	586,288	406,767
Proceeds from repayments and maturities of securities held to maturity	42,653	0
Proceeds from sales of premises and equipment	4,287	2,128
Proceeds from redemption of Federal Home Loan Bank stock	1	91,080
Proceeds from sales of other real estate and other personal property owned	132	1,034
Proceeds from bank owned life insurance death benefit	671	1,050
Net cash used in investing activities	(1,933,439)	(1,297,189)
Cash Flows From Financing Activities
Net increase in deposits	2,083,537	2,915,565
Net decrease in sweep repurchase agreements	(33,819)	(37,471)
Proceeds from FHLB advances	20	1,331,000
Proceeds from FRB borrowings	10	222,010
Proceeds from other borrowings	0	9,222
Proceeds from employee stock purchase plan	2,351	2,028
Repayment of FHLB advances	(20)	(2,277,000)
Repayment of FRB borrowings	(10)	(222,010)
Repayments of other borrowings	0	(9,222)
Payments for common stock dividends	(59,922)	(75,630)
Payments for purchase of treasury stock	0	(20,000)
Payments for purchase and retirement of common stock	4,100	2,498
Net cash provided by financing activities	1,988,047	1,835,994
Increase (decrease) in cash and cash equivalents	243,709	682,572
Cash and cash equivalents at beginning of period	653,766	247,673
Cash and cash equivalents at end of period	897,475	930,245
Supplemental Information:
Cash paid for interest	6,085	15,913
Income Taxes Paid, Net	45,122	32,745
Non-cash investing and financing activities
Securities transfer from AFS to HTM, fair value	2,012,123	0
Loans transferred to OREO	0	1,033
Premises and equipment expenditures incurred but not yet paid	87	301
Change in dividends payable included in other liabilities	$ 23,927	$ 522