Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating Activities
Net income	$ 144,187	$ 158,429
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	5,498	(5,605)
Net amortization of debt securities	17,854	19,615
Net amortization of purchase accounting adjustments and deferred loan fees and costs	7,070	4,113
Origination of loans held for sale	(492,225)	(827,653)
Proceeds from loans held for sale	545,318	976,517
Gain on sale of loans	(14,011)	(37,730)
Gain on sale of debt securities	(186)	(223)
Bank-owned life insurance income, net	(1,827)	(1,352)
Stock-based compensation, net of tax benefits	3,081	2,408
Depreciation and amortization of premises and equipment	12,168	10,446
Gain on sale and write-downs of other real estate owned, net	(1)	(247)
Amortization of core deposit intangibles	5,329	4,976
Amortization of investments in variable interest entities	8,600	6,474
Net (increase) decrease in accrued interest receivable	(3,666)	5,045
Net increase in other assets	(24,304)	(13,239)
Net decrease in accrued interest payable	(75)	(11,017)
Net increase (decrease) in other liabilities	3,856	(872)
Net cash provided by operating activities	216,666	290,085
Investing Activities
Maturities, prepayments and calls of available-for-sale debt securities	668,563	611,077
Purchases of available-for-sale debt securities	(410,032)	(2,351,093)
Maturities, prepayments and calls of held-to-maturity debt securities	100,111	6,360
Purchases of held-to-maturity debt securities	(482,727)	0
Principal collected on loans	3,266,467	3,281,147
Loan originations	(4,256,894)	(3,446,582)
Net additions to premises and equipment	(12,696)	1,435
Proceeds from sale of other real estate owned	46	2,679
Proceeds from redemption of non-marketable equity securities	71,836	3
Purchases of non-marketable equity securities	(94,998)	0
Proceeds from bank-owned life insurance	1,304	2,112
Investments in variable interest entities	(26,035)	(10,711)
Net cash used in investing activities	(1,175,055)	(1,903,573)
Financing Activities
Net increase in deposits	446,927	1,963,419
Net decrease in securities sold under agreements to repurchase	(52,597)	(9,382)
Net increase in short-term Federal Home Loan Bank advances	580,000	0
Net increase in other borrowed funds	11,060	(7,012)
Cash dividends paid	(47,851)	(44,142)
Tax withholding payments for stock-based compensation	(1,430)	(1,495)
Proceeds from stock option exercises	0	165
Net cash provided by financing activities	936,109	1,901,553
Net (decrease) increase in cash, cash equivalents and restricted cash	(22,280)	288,065
Cash, cash equivalents and restricted cash at beginning of period	437,686	633,142
Cash, cash equivalents and restricted cash at end of period	415,406	921,207
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	11,235	10,099
Cash paid during the period for income taxes	26,710	49,663
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	406	1,459
Right-of-use assets obtained in exchange for operating lease liabilities	11,805	720
Dividends declared during the period but not paid	$ 36,730	$ 30,697