Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net earnings	$ 350,755	$ 350,298
Depreciation and amortization	28,266	25,788
Amortization of net premiums on securities available-for-sale	11,078	19,489
Amortization of intangible assets	14,573	17,520
Amortization of operating lease ROU assets	22,028	0
Provision for credit losses	19,000	33,000
(Gain) loss on sale of foreclosed assets	(406)	35
Provision for losses on foreclosed assets	54	65
Gain on sale of loans and leases	(1,091)	(4,675)
Gain on sale of premises and equipment	(34)	(13)
Gain on sale of securities	(25,261)	(7,390)
Gain on BOLI death benefit	0	(437)
Unrealized (gain) loss on derivatives and foreign currencies, net	(16)	76
Earned stock compensation	19,834	22,882
Decrease (increase) in deferred income taxes, net	14,714	(8,790)
Decrease in other assets	35,631	52,275
Decrease in accrued interest payable and other liabilities	(41,530)	(36,303)
Net cash provided by operating activities	447,595	463,820
Cash flows from investing activities:
Net increase in loans and leases	(894,624)	(446,880)
Proceeds from sales of loans and leases	102,507	646,587
Proceeds from maturities and paydowns of securities available-for-sale	238,487	231,474
Proceeds from sales of securities available-for-sale	1,554,805	500,101
Purchases of securities available-for-sale	(1,444,720)	(910,298)
Net redemptions (purchases) of Federal Home Loan Bank stock	5,238	(10,287)
Proceeds from sales of foreclosed assets	4,322	57
Proceeds from sales of premises and equipment	60	49
Proceeds from BOLI death benefit	555	1,901
Purchases of premises and equipment, net	(10,990)	(9,250)
Net increase in equipment leased to others under operating leases	(19,981)	(6,000)
Net cash used in investing activities	(464,341)	(2,546)
Cash flows from financing activities:
Net decrease in noninterest-bearing deposits	(446,400)	(671,016)
Net increase (decrease) in interest-bearing deposits	1,310,432	(312,429)
Net (decrease) increase in borrowings	(118,083)	1,045,824
Net decrease in subordinated debentures	0	(12,372)
Common stock repurchased and restricted stock surrendered	(161,928)	(313,796)
Cash dividends paid	(217,041)	(214,136)
Net cash provided by (used in) financing activities	366,980	(477,925)
Net increase (decrease) in cash, cash equivalents, and restricted cash	350,234	(16,651)
Cash, cash equivalents, and restricted cash, beginning of period	385,767	398,437
Cash, cash equivalents, and restricted cash, end of period	736,001	381,786
Supplemental disclosures of cash flow information:
Cash paid for interest	154,212	78,884
Cash paid for income taxes	89,505	62,525
Loans transferred to foreclosed assets	37	3,235
Transfers from loans held for investment to loans held for sale	$ 25,124	$ 0