Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash Flows From Operating Activities
Net income	$ 106,892	$ 51,210
Adjustments to reconcile net income to net cash provided by operating activities
Provision (recapture) for credit losses	(6,300)	75,000
Stock-based compensation expense	6,936	4,909
Depreciation, amortization and accretion	7,056	10,382
Investment securities gain, net	314	16,674
Net realized gain on sale of premises and equipment, loans held for investment and OPPO	279	705
Net realized loss on sale and valuation adjustments of OREO	(40)	(18)
Gain on bank owned life insurance death benefit	209	0
Originations of loans held for sale	195,632	217,017
Proceeds from sales of loans held for sale	208,789	205,932
Change in fair value of loans held for sale	145	0
Net change in:
Interest receivable	2,484	(12,310)
Interest payable	(49)	(219)
Other assets	12,583	(93,919)
Other liabilities	(14,700)	76,500
Net cash provided by operating activities	127,442	83,107
Cash Flows From Investing Activities
Loans originated, net of principal collected	(177,399)	(1,026,250)
Purchases of debt securities available for sale	(1,527,512)	(259,236)
Purchases of debt securities held to maturity	(22,915)	0
Purchases of loans held for investment	74,383	0
Purchases of premises and equipment	(3,087)	(4,490)
Purchases of FHLB stock	0	(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	385,408	265,072
Proceeds from repayments and maturities of securities held to maturity	8,711	0
Proceeds from sales of premises and equipment	4,296	932
Proceeds from redemption of Federal Home Loan Bank stock	0	85,080
Proceeds from sales of other real estate and other personal property owned	132	353
Proceeds from bank owned life insurance death benefit	671	1,050
Net cash used in investing activities	(1,379,164)	(793,624)
Cash Flows From Financing Activities
Net increase in deposits	1,475,570	2,446,782
Net decrease in sweep repurchase agreements	(2,865)	(12,958)
Proceeds from FHLB advances	10	1,331,000
Proceeds from FRB borrowings	0	222,010
Proceeds from other borrowings	0	9,222
Proceeds from exercise of stock options and employee stock purchase plan	1,098	945
Repayment of FHLB advances	(10)	(2,127,000)
Repayment of FRB borrowings	0	222,010
Repayments of other borrowings	0	9,222
Payments for common stock dividends	(40,244)	(55,750)
Purchase of treasury stock	0	(20,000)
Purchase and retirement of common stock	4,071	2,482
Net cash provided by financing activities	1,429,488	1,560,537
Increase (decrease) in cash and cash equivalents	177,766	850,020
Cash and cash equivalents at beginning of period	653,766	247,673
Cash and cash equivalents at end of period	831,532	1,097,693
Supplemental Information:
Cash paid for interest	4,082	13,075
Income Taxes Paid, Net	28,474	21,501
Non-cash investing and financing activities
Securities transfer from AFS to HTM, fair value	2,012,123	0
Loans transferred to OREO	0	558
Premises and equipment expenditures incurred but not yet paid	0	9
Change in dividends payable on unvested shares included in other liabilities	$ (122)	$ 296