Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities:
Net income	$ 263,625	$ 220,542
Adjustments to reconcile net income to net cash from operating activities:
Provision for loan losses	27,358	42,734
Deferred tax expense (benefit)	(9,505)	(11,629)
Accretion of loan discount	(11,567)	(11,893)
Securities premium amortization (discount accretion), net	66,455	59,071
Net (gain) loss on securities transactions	4,917	(14,866)
Depreciation and amortization	35,819	35,712
Net (gain) loss on sale/write-down of assets/foreclosed assets	(2,045)	(373)
Stock-based compensation	9,013	7,998
Net tax benefit from stock-based compensation	5,844	1,610
Earnings on life insurance policies	(2,367)	(2,678)
Net change in:
Trading account securities	(3,018)	418
Accrued interest receivable and other assets	10,495	11,134
Accrued interest payable and other liabilities	(39,580)	(2,806)
Net cash from operating activities	355,444	334,974
Investing Activities:
Securities held-to-maturity - Purchases	0	0
Securities held-to-maturity - Sales	0	135,610
Securities held to maturity: Maturities, calls and principal repayments	780,562	227,760
Securities available for sale:
Purchases	(9,138,457)	(10,079,302)
Sales	8,993,963	9,040,245
Maturities, calls and principal repayments	283,278	270,737
Proceeds from sale of loans	0	30,470
Net change in loans	(745,702)	(142,698)
Benefits received on life insurance policies	462	906
Proceeds from sales of premises and equipment	1,553	1,517
Purchases of premises and equipment	(23,796)	(32,647)
Proceeds from sales of repossessed properties	517	297
Net cash from investing activities	152,380	(547,105)
Financing Activities:
Net change in deposits	591,694	763,953
Net change in short-term borrowings	20,927	(89,220)
Proceeds from issuance of subordinated notes	98,434	0
Principal payments on subordinated notes	(100,000)	0
Proceeds from stock option exercises	45,422	47,873
Purchase of treasury stock	(100,042)	0
Cash dividends – preferred stock	(6,047)	(6,047)
Cash dividends – common stock	(107,754)	(100,563)
Net cash from financing activities	442,634	615,996
Net change in cash and cash equivalents	950,458	403,865
Cash and equivalents at beginning of period	4,141,445	3,591,523
Cash and equivalents at end of period	$ 5,091,903	$ 3,995,388