Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest income
Loans and leases, including fees	$ 979,969	$ 898,038
Investment securities
Fully taxable	82,852	95,124
Exempt from federal taxes	248	430
Deposits at banks	18,677	12,162
Other	404	279
Total interest income	1,082,150	1,006,033
Interest expense
Savings and interest-checking deposits	40,527	25,634
Time deposits	10,936	18,998
Deposits at Cayman Islands office	381	265
Short-term borrowings	883	216
Long-term borrowings	53,906	46,660
Total interest expense	106,633	91,773
Net interest income	975,517	914,260
Provision for credit losses	43,000	55,000
Net interest income after provision for credit losses	932,517	859,260
Other income
Mortgage banking revenues	87,306	84,692
Service charges on deposit accounts	105,115	104,176
Trust income	131,375	120,015
Brokerage services income	13,392	17,384
Trading account and foreign exchange gains	4,637	9,691
Gain (loss) on bank investment securities	(9,431)
Other revenues from operations	126,302	110,887
Total other income	458,696	446,845
Other expense
Salaries and employee benefits	463,428	449,741
Equipment and net occupancy	74,797	74,366
Outside data processing and software	48,429	44,301
FDIC assessments	20,280	28,827
Advertising and marketing	16,248	16,110
Printing, postage and supplies	9,319	9,708
Amortization of core deposit and other intangible assets	6,632	8,420
Other costs of operations	294,211	156,379
Total other expense	933,344	787,852
Income before taxes	457,869	518,253
Income taxes	105,259	169,326
Net income	352,610	348,927
Net income available to common shareholders
Basic	332,748	328,562
Diluted	$ 332,749	$ 328,567
Net income per common share
Basic	$ 2.24	$ 2.13
Diluted	2.23	2.12
Cash dividends per common share	$ 0.75	$ 0.75
Average common shares outstanding
Basic	148,688	154,427
Diluted	148,905	154,949