Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating Activities:
Net income	$ 335,665	$ 263,625
Adjustments to reconcile net income to net cash from operating activities:
Provision for loan losses	17,846	27,358
Deferred tax expense (benefit)	39,198	(9,505)
Accretion of loan discounts	(10,470)	(11,567)
Securities premium amortization (discount accretion), net	73,748	66,455
Net (gain) loss on securities transactions	113	4,917
Depreciation and amortization	37,452	35,819
Net (gain) loss on sale/write-down of assets/foreclosed assets	(6,122)	(2,045)
Stock-based compensation	9,556	9,013
Net tax benefit from stock-based compensation	3,378	5,844
Earnings on life insurance policies	(2,510)	(2,367)
Net change in:
Trading account securities	(1,094)	(3,018)
Accrued interest receivable and other assets	(19,047)	10,495
Accrued interest payable and other liabilities	(17,545)	(39,580)
Net cash from operating activities	460,168	355,444
Investing Activities:
Securities held-to-maturity - Purchases	(1,500)	0
Securities held-to-maturity - Sales	0	0
Securities held to maturity: Maturities, calls and principal repayments	300,340	780,562
Securities available for sale:
Purchases	(14,983,642)	(9,138,457)
Sales	13,838,566	8,993,963
Maturities, calls and principal repayments	182,028	283,278
Proceeds from sale of loans	21,318	0
Net change in loans	(718,551)	(745,702)
Benefits received on life insurance policies	384	462
Proceeds from sales of premises and equipment	12,859	1,553
Purchases of premises and equipment	(56,781)	(23,796)
Proceeds from sales of repossessed properties	1,106	517
Net cash from investing activities	(1,403,873)	152,380
Financing Activities:
Net change in deposits	(523,535)	591,694
Net change in short-term borrowings	(64,047)	20,927
Proceeds from issuance of subordinated notes	0	98,434
Principal payments on subordinated notes	0	(100,000)
Proceeds from stock option exercises	26,567	45,422
Purchase of treasury stock	(70)	(100,042)
Cash dividends paid on preferred stock	(6,047)	(6,047)
Cash dividends paid on common stock	(122,721)	(107,754)
Net cash from financing activities	(689,853)	442,634
Net change in cash and cash equivalents	(1,633,558)	950,458
Cash and equivalents at beginning of period	5,053,047	4,141,445
Cash and equivalents at end of period	$ 3,419,489	$ 5,091,903