Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flows From Operating Activities
Net income	$ 95,944	$ 148,322
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	82,400	1,879
Stock-based compensation expense	7,918	6,827
Depreciation, amortization and accretion	14,456	26,150
Investment securities gain, net	16,674	2,132
Net realized gain on sale of premises and equipment, loans held for investment and OPPO	953	6,787
Net realized gain on sale and valuation adjustments of OREO	64	602
Gain on bank owned life insurance death benefit	0	2,975
Originations of loans held for sale	356,962	134,634
Proceeds from sales of loans held for sale	350,273	123,447
Net change in:
Interest receivable	(9,879)	(3,180)
Interest payable	(399)	632
Other assets	(53,996)	(31,840)
Other liabilities	31,703	29,706
Net cash provided by operating activities	143,767	154,813
Cash Flows From Financing Activities
Loans originated, net of principal collected	(938,624)	(305,581)
Purchases of debt securities available for sale	(996,951)	(649,133)
Purchases of loans held for investment	0	57,075
Purchases of premises and equipment	(7,538)	(5,833)
Purchases of FHLB stock	(53,240)	(190,800)
Proceeds from sale of debt securities, available-for-sale	194,105	259,554
Proceeds from sale of equity securities	3,000	0
Proceeds from principal repayments and maturities of debt securities available for sale	406,767	287,479
Proceeds from sales of premises and equipment	2,128	7,735
Proceeds from redemption of Federal Home Loan Bank stock	91,080	187,080
Proceeds from sales of other real estate and other personal property owned	1,034	6,433
Proceeds from bank owned life insurance death benefit	1,050	0
Net cash used in investing activities	(1,297,189)	(460,141)
Cash Flows From Financing Activities
Net increase in deposits	2,915,565	397,893
Net decrease in sweep repurchase agreements	(37,471)	(36,605)
Proceeds from FHLB advances	1,331,000	4,770,000
Proceeds from FRB borrowings	222,010	36,000
Proceeds from other borrowings	9,222	100
Proceeds from exercise of stock options and employee stock purchase plan	2,028	2,025
Repayment of FHLB advances	(2,277,000)	(4,677,000)
Repayment of FRB borrowings	222,010	36,000
Repayments of other borrowings	9,222	100
Payments for common stock dividends	(75,630)	(81,822)
Purchase of treasury stock	(20,000)	(45,380)
Purchase and retirement of common stock	2,498	2,765
Net cash provided by financing activities	1,835,994	326,346
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	682,572	21,018
Cash and cash equivalents at beginning of period	247,673	277,587
Cash and cash equivalents at end of period	930,245	298,605
Supplemental Information:
Cash paid for interest	15,913	27,623
Cash paid for income tax, net of refunds	32,745	33,134
Non-cash investing and financing activities
Loans transferred to OREO	1,033	386
Premises and equipment expenditures incurred but not yet paid	301	152
Change in dividends payable on unvested shares included in other liabilities	$ 522	$ 252