Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows From Operating Activities
Net income	$ 51,853	$ 14,628
Adjustments to reconcile net income to net cash provided by operating activities
Provision (recapture) for credit losses	(800)	41,500
Stock-based compensation expense	3,028	2,172
Depreciation, amortization and accretion	1,433	13,151
Investment securities gain, net	0	249
Net realized (gain) loss on sale of premises and equipment, loans held for investment and OPPO	(6)	25
Net realized gain on sale and valuation adjustments of OREO	100	0
Gain on bank owned life insurance death benefit	209	0
Originations of loans held for sale	107,104	58,199
Proceeds from sales of loans held for sale	107,320	66,216
Increase (Decrease) in Mortgage Loans Held-for-sale	89	0
Net change in:
Interest receivable	2,164	2,262
Interest payable	494	2,325
Other assets	11,525	(63,141)
Other liabilities	(10,627)	44,725
Net cash provided by operating activities	59,072	65,365
Cash Flows From Financing Activities
Loans originated, net of principal collected	(164,856)	(197,362)
Purchases of debt securities available for sale	(608,854)	(37,472)
Purchases of loans held for investment	74,383	0
Purchases of premises and equipment	(805)	(1,650)
Purchases of FHLB stock	0	(51,240)
Proceeds from sale of debt securities, available-for-sale	0	194,105
Proceeds from principal repayments and maturities of debt securities available for sale	180,380	134,641
Proceeds from sales of premises and equipment	0	31
Proceeds from redemption of Federal Home Loan Bank stock	0	61,080
Proceeds from sales of other real estate and other personal property owned	132	50
Proceeds from bank owned life insurance death benefit	671	1,050
Net cash provided by (used in) investing activities	(667,715)	103,233
Cash Flows From Financing Activities
Net increase in deposits	897,604	128,059
Net decrease in sweep repurchase agreements	(35,235)	(35,185)
Proceeds from FHLB advances	0	1,281,000
Proceeds from FRB borrowings	0	182,010
Proceeds from other borrowings	0	5,000
Proceeds from exercise of stock options and employee stock purchase plan	1,098	945
Repayment of FHLB advances	0	(1,527,000)
Repayment of FRB borrowings	0	177,010
Payments for common stock dividends	(20,110)	(35,860)
Purchase of treasury stock	0	(20,000)
Purchase and retirement of common stock	3,995	2,474
Net cash provided by (used in) financing activities	839,362	(200,515)
Increase (decrease) in cash and cash equivalents	230,719	(31,917)
Cash and cash equivalents at beginning of period	653,766	247,673
Cash and cash equivalents at end of period	884,485	215,756
Supplemental Information:
Cash paid for interest	1,553	6,150
Income Taxes Paid, Net	(1)	12
Non-cash investing and financing activities
Premises and equipment expenditures incurred but not yet paid	43	238
Change in dividends payable on unvested shares included in other liabilities	$ (49)	$ 157