Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities
Net income	$ 82,472	$ 38,295
Adjustments to reconcile net income to net cash provided by operating activities
(Release of) provision for loan losses	(3,880)	37,200
Depreciation and amortization	6,636	8,471
Accretion of deferred loan fees and premiums, net	(14,767)	(3,155)
Deferred income tax expense	5,407	1,773
Amortization of investment security premiums and discounts	6,397	1,656
Right-of-use asset amortization	6,130	6,042
Increase in cash surrender value of bank-owned life insurance	(1,073)	(1,155)
Gain on sale of securities available for sale, net	(1,165)	(285)
Amortization of gains from terminated interest rate swaps	(16,493)	(373)
Employee Stock Ownership Plan expense	4,679	0
Other	248	(128)
Change in:
Trading securities	0	961
Loans held for sale	(1,583)	(2,965)
Prepaid pension expense	1,676	(28,432)
Other assets	9,746	(133,413)
Other liabilities	(24,794)	77,509
Net cash provided by operating activities	59,636	2,001
Investing activities
Proceeds from sales of securities available for sale	23,237	9,098
Proceeds from maturities and principal paydowns of securities available for sale	381,123	153,542
Purchases of securities available for sale	(2,138,024)	(171,226)
Proceeds from sale of Federal Home Loan Bank stock	0	749
Purchases of Federal Home Loan Bank stock	(1,796)	(527)
Contributions to low income housing tax credit investments	(4,553)	(7,435)
Contributions to other equity investments	(1,920)	(1,092)
Distributions from other equity investments	170	54
Net decrease (increase) in outstanding loans	126,868	(997,881)
Acquisitions, net of cash and cash equivalents acquired	(4,354)	0
Purchased banking premises and equipment, net	(1,809)	(2,146)
Proceeds from sale of premises held for sale	736	0
Net cash used in investing activities	(1,620,322)	(1,016,864)
Financing activities
Net increase in demand, savings, interest checking, and money market investment deposit accounts	1,107,351	2,315,592
Net decrease in time deposits	(12,702)	(20,219)
Net increase (decrease) in borrowed funds	393	(206,240)
Contingent consideration paid	(79)	(158)
Payment of deferred offering costs	0	(4,153)
Dividends declared and paid to common shareholders	(24,100)	0
Net cash provided by financing activities	1,070,863	2,084,822
Net (decrease) increase in cash, cash equivalents, and restricted cash	(489,823)	1,069,959
Cash, cash equivalents, and restricted cash at beginning of period	2,054,070	362,602
Cash, cash equivalents, and restricted cash at end of period	1,564,247	1,432,561
Supplemental disclosure of cash flow information
Interest paid	2,127	10,533
Income taxes	35,122	14,976
Non-cash activities
Net increase in capital commitments relating to low income housing tax credit projects	14,446	13,214
Initial recognition of operating lease right-of-use assets upon adoption of Accounting Standards Update 2016-02	0	92,948
Initial recognition of operating lease liabilities upon adoption of Accounting Standards Update 2016-02	$ 0	$ 96,426