Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Interest income
Loans and leases, including fees	$ 898,038	$ 863,385
Investment securities
Fully taxable	95,124	98,015
Exempt from federal taxes	430	795
Deposits at banks	12,162	10,337
Other	279	302
Total interest income	1,006,033	972,834
Interest expense
Savings and interest-checking deposits	25,634	16,305
Time deposits	18,998	24,322
Deposits at Cayman Islands office	265	193
Short-term borrowings	216	2,162
Long-term borrowings	46,660	57,888
Total interest expense	91,773	100,870
Net interest income	914,260	871,964
Provision for credit losses	55,000	49,000
Net interest income after provision for credit losses	859,260	822,964
Other income
Mortgage banking revenues	84,692	82,063
Service charges on deposit accounts	104,176	102,405
Trust income	120,015	111,077
Brokerage services income	17,384	16,004
Trading account and foreign exchange gains	9,691	7,458
Gain on bank investment securities		4
Other revenues from operations	110,887	101,922
Total other income	446,845	420,933
Other expense
Salaries and employee benefits	449,862	431,785
Equipment and net occupancy	74,366	74,178
Outside data processing and software	44,301	43,015
FDIC assessments	28,827	25,225
Advertising and marketing	16,110	21,454
Printing, postage and supplies	9,708	11,986
Amortization of core deposit and other intangible assets	8,420	12,319
Other costs of operations	156,258	156,133
Total other expense	787,852	776,095
Income before taxes	518,253	467,802
Income taxes	169,326	169,274
Net income	348,927	298,528
Net income available to common shareholders
Basic	328,562	275,744
Diluted	$ 328,567	$ 275,748
Net income per common share
Basic	$ 2.13	$ 1.74
Diluted	2.12	1.73
Cash dividends per common share	$ 0.75	$ 0.70
Average common shares outstanding
Basic	154,427	158,734
Diluted	154,949	159,181