Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net earnings	$ 273,781	$ 266,519
Depreciation and amortization	23,798	24,761
Amortization of net premiums on securities available-for-sale	30,238	28,012
Amortization of intangible assets	9,178	13,341
Provision for credit losses	51,346	42,514
Gain on sale of foreclosed assets	(282)	(837)
Provision for losses on foreclosed assets	2,138	0
Gain on sale of loans and leases	(4,209)	(790)
Gain on sale of premises and equipment	(388)	(23)
Gain on sale of securities	(2,788)	(8,970)
Gain on BOLI death benefit	(1,050)	(539)
Unrealized gain on derivatives and foreign currencies, net	(449)	(374)
Earned stock compensation	20,198	17,275
Loss on sale of PWEF leasing unit	0	720
Tax effect included in stockholders' equity of restricted stock vesting	0	(4,226)
Decrease in accrued and deferred income taxes, net	10,164	74,946
(Increase) decrease in other assets	(32,765)	1,224
Decrease in accrued interest payable and other liabilities	(20,738)	(23,600)
Net cash provided by operating activities	358,172	429,953
Cash flows from investing activities:
Net increase in loans and leases	(567,291)	(514,224)
Proceeds from sales of loans and leases	293,808	106,109
Proceeds from maturities and paydowns of securities available-for-sale	329,876	184,644
Proceeds from sales of securities available-for-sale	185,533	392,841
Purchases of securities available-for-sale	(804,710)	(303,742)
Net redemptions of Federal Home Loan Bank stock	4,620	324
Proceeds from sales of foreclosed assets	1,455	7,973
Purchases of premises and equipment, net	(5,892)	(6,185)
Proceeds from sales of premises and equipment	10,306	24
Proceeds from sale of PWEF leasing unit	0	138,955
Proceeds from BOLI death benefit	2,478	3,238
Net increase of equipment leased to others under operating leases	(17,956)	(15,802)
Net cash used in investing activities	(567,773)	(5,845)
Cash flows from financing activities:
Net increase in noninterest-bearing deposits	255,874	352,784
Net increase (decrease) in interest-bearing deposits	649,776	(371,005)
Net decrease in borrowings	(655,413)	(78,873)
Restricted stock surrendered	(7,793)	(4,611)
Tax effect included in stockholders' equity of restricted stock vesting	0	4,226
Cash dividends paid	(182,495)	(182,750)
Net cash provided by (used in) financing activities	59,949	(280,229)
Net (decrease) increase in cash and cash equivalents	(149,652)	143,879
Cash and cash equivalents, beginning of period	419,670	396,486
Cash and cash equivalents, end of period	270,018	540,365
Supplemental disclosures of cash flow information:
Cash paid for interest	48,402	41,392
Cash paid for income taxes	146,321	82,721
Loans transferred to foreclosed assets	580	129
Transfers from loans held for investment to loans held for sale	$ 175,158	$ 0