Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities
Net income	$ 223,525	$ 234,048
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	13,839	(4,880)
Net amortization of debt securities	24,274	32,934
Net amortization of purchase accounting adjustments and deferred loan fees and costs	8,533	(1,003)
Origination of loans held for sale	(639,726)	(1,184,305)
Proceeds from loans held for sale	715,700	1,372,592
Gain on sale of loans	(17,857)	(51,632)
Gain on sale of debt securities	(101)	(55)
Bank-owned life insurance income, net	(2,698)	(2,027)
Stock-based compensation, net of tax benefits	4,218	3,440
Depreciation and amortization of premises and equipment	18,952	15,593
Gain on sale and write-downs of other real estate owned, net	(125)	(127)
Amortization of core deposit intangibles	7,994	7,464
Amortization of investments in variable interest entities	13,051	9,520
Net increase in accrued interest receivable	(16,627)	(4,201)
Net increase in other assets	(20,827)	(5,430)
Net increase (decrease) in accrued interest payable	331	(868)
Net increase (decrease) in other liabilities	18,291	(3,753)
Net cash provided by operating activities	350,747	417,310
Investing Activities
Maturities, prepayments and calls of available-for-sale debt securities	914,036	1,026,010
Purchases of available-for-sale debt securities	(435,807)	(4,035,869)
Maturities, prepayments and calls of held-to-maturity debt securities	159,349	25,480
Purchases of held-to-maturity debt securities	(511,195)	(125,527)
Principal collected on loans	4,530,150	4,825,177
Loan originations	(5,984,286)	(5,062,750)
Net additions to premises and equipment	(16,909)	(4,187)
Proceeds from sale of other real estate owned	997	3,246
Proceeds from redemption of non-marketable equity securities	132,667	180
Purchases of non-marketable equity securities	(160,798)	(2)
Proceeds from bank-owned life insurance	2,217	2,112
Investments in variable interest entities	(32,866)	(14,799)
Net cash used in investing activities	(1,402,445)	(3,360,929)
Financing Activities
Net increase in deposits	543,134	2,705,870
Net (decrease) increase in securities sold under agreements to repurchase	(133,311)	36,356
Net increase in short-term Federal Home Loan Bank advances	705,000	0
Net decrease (increase) in other borrowed funds	10,415	(6,897)
Cash dividends paid	(84,414)	(74,709)
Tax withholding payments for stock-based compensation	(1,600)	(1,520)
Proceeds from stock option exercises	0	265
Net cash provided by financing activities	1,039,224	2,659,365
Net decrease in cash, cash equivalents and restricted cash	(12,474)	(284,254)
Cash, cash equivalents and restricted cash at beginning of period	437,686	633,142
Cash, cash equivalents and restricted cash at end of period	425,212	348,888
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	19,904	14,223
Cash paid during the period for income taxes	40,917	58,645
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Transfer of debt securities from available-for-sale to held-to-maturity	2,154,475	844,020
Transfer of loans to other real estate owned	896	1,481
Right-of-use assets obtained in exchange for new lease liabilities	24,023	801
Dividends declared during the period but not paid	$ 36,817	$ 30,761