CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income	$ 57,693	$ 38,865
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for credit losses		41,200
Depreciation, amortization and accretion, net	13,643	17,121
Deferred income tax provision	355	6,624
Stock-based compensation	3,037	2,802
Other losses (gains)	1,090	(15)
Originations of loans held for sale	(61,552)	(41,062)
Proceeds from sales of loans held for sale	67,067	35,435
Net gains on sales of loans originated for investment and held for sale	(1,486)	(2,459)
Net gains on investment securities		(85)
Change in assets and liabilities:
Net decrease (increase) in other assets	27,030	(22,164)
Net increase (decrease) in other liabilities	47,323	(128,111)
Net cash provided by (used in) operating activities	154,200	(51,849)
Available-for-sale securities:
Proceeds from maturities and principal repayments	448,655	259,447
Proceeds from calls and sales	145	78,472
Purchases	(1,178,760)	(272,324)
Other investments:
Proceeds from sales	2,404	8,492
Purchases	(14,515)	(9,196)
Loans:
Net increase in loans and leases resulting from originations and principal repayments	(45,193)	(276,113)
Proceeds from sales of loans originated for investment	220	132,011
Purchases of loans	(558)	(30,244)
Proceeds from bank-owned life insurance		906
Purchases of premises, equipment and software	(3,791)	(14,728)
Proceeds from sales of premises and equipment		185
Proceeds from sales of other real estate owned		69
Other	(1,171)	(1,035)
Net cash used in investing activities	(792,564)	(124,058)
Cash flows from financing activities
Net increase in deposits	905,958	575,008
Dividends paid	(33,812)	(33,782)
Stock tendered for payment of withholding taxes	(2,373)	(1,504)
Common stock repurchased	(9,543)	(5,000)
Net cash provided by financing activities	860,230	534,722
Net increase in cash and cash equivalents	221,866	358,815
Cash and cash equivalents at beginning of period	1,040,944	694,017
Cash and cash equivalents at end of period	1,262,810	1,052,832
Supplemental disclosures
Interest paid	8,894	24,163
Income taxes paid, net of income tax refunds	981	5,165
Noncash investing and financing activities:
Operating lease right-of-use assets obtained in exchange for new lease obligations	6,864
Transfers from loans and leases to loans held for sale	$ 1,840	$ 131,201