Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest income
Loans and leases, including fees	$ 924,640	$ 867,478	$ 1,822,678	$ 1,730,863
Investment securities
Fully taxable	92,996	91,184	188,120	189,199
Exempt from federal taxes	379	663	809	1,458
Deposits at banks	12,213	10,993	24,375	21,330
Other	185	303	464	605
Total interest income	1,030,413	970,621	2,036,446	1,943,455
Interest expense
Savings and interest-checking deposits	30,543	20,534	56,177	36,839
Time deposits	16,303	26,867	35,301	51,189
Deposits at Cayman Islands office	281	181	546	374
Short-term borrowings	378	1,143	594	3,305
Long-term borrowings	44,708	58,077	91,368	115,965
Total interest expense	92,213	106,802	183,986	207,672
Net interest income	938,200	863,819	1,852,460	1,735,783
Provision for credit losses	52,000	32,000	107,000	81,000
Net interest income after provision for credit losses	886,200	831,819	1,745,460	1,654,783
Other income
Mortgage banking revenues	86,163	89,383	170,855	171,446
Service charges on deposit accounts	106,057	103,872	210,233	206,277
Trust income	126,797	120,450	246,812	231,527
Brokerage services income	16,617	16,272	34,001	32,276
Trading account and foreign exchange gains	8,084	13,222	17,775	20,680
Gain (loss) on bank investment securities	(17)	264	(17)	268
Other revenues from operations	117,115	104,791	228,002	206,713
Total other income	460,816	448,254	907,661	869,187
Other expense
Salaries and employee benefits	398,900	398,675	848,762	830,460
Equipment and net occupancy	73,797	75,724	148,163	149,902
Outside data processing and software	44,575	42,509	88,876	85,524
FDIC assessments	25,353	22,370	54,180	47,595
Advertising and marketing	16,324	22,613	32,434	44,067
Printing, postage and supplies	8,957	9,907	18,665	21,893
Amortization of core deposit and other intangible assets	8,113	11,418	16,533	23,737
Other costs of operations	174,616	166,679	330,874	322,812
Total other expense	750,635	749,895	1,538,487	1,525,990
Income before taxes	596,381	530,178	1,114,634	997,980
Income taxes	215,328	194,147	384,654	363,421
Net income	381,053	336,031	729,980	634,559
Net income available to common shareholders
Basic	360,658	312,968	689,208	588,697
Diluted	$ 360,662	$ 312,974	$ 689,217	$ 588,707
Net income per common share
Basic	$ 2.36	$ 1.98	$ 4.49	$ 3.72
Diluted	2.35	1.98	4.47	3.71
Cash dividends per common share	$ 0.75	$ 0.70	$ 1.50	$ 1.40
Average common shares outstanding
Basic	152,857	157,802	153,638	158,268
Diluted	153,276	158,341	154,108	158,761