Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Cash and due from banks	$ 1,291,664	$ 1,420,888
Interest-bearing deposits at banks	6,135,434	5,078,903
Federal funds sold	1,000
Trading account	141,134	132,909
Investment securities (includes pledged securities that can be sold or repledged of $470,906 at March 31, 2018; $487,151 at December 31, 2017)
Available for sale (cost: $10,508,620 at March 31, 2018; $10,938,796 at December 31, 2017)	10,297,856	10,896,284
Held to maturity (fair value: $3,160,215 at March 31, 2018; $3,341,762 at December 31, 2017)	3,228,756	3,353,213
Equity and other securities (cost: $526,593 at March 31, 2018; $415,028 at December 31, 2017)	539,952	415,028
Total investment securities	14,066,564	14,664,525
Loans and leases	87,967,757	88,242,886
Unearned discount	(257,008)	(253,903)
Loans and leases, net of unearned discount	87,710,749	87,988,983
Allowance for credit losses	(1,019,671)	(1,017,198)
Loans and leases, net	86,691,078	86,971,785
Premises and equipment	628,706	646,451
Goodwill	4,593,112	4,593,112
Core deposit and other intangible assets	64,957	71,589
Accrued interest and other assets	5,009,175	5,013,325
Total assets	118,622,824	118,593,487
Liabilities
Noninterest-bearing deposits	31,817,516	33,975,180
Savings and interest-checking deposits	52,724,608	51,698,008
Time deposits	6,126,442	6,580,962
Deposits at Cayman Islands office	278,064	177,996
Total deposits	90,946,630	92,432,146
Short-term borrowings	1,626,129	175,099
Accrued interest and other liabilities	1,749,320	1,593,993
Long-term borrowings	8,591,051	8,141,430
Total liabilities	102,913,130	102,342,668
Shareholders' equity
Preferred stock, $1.00 par, 1,000,000 shares authorized; Issued and outstanding: Liquidation preference of $1,000 per share: 731,500 shares at March 31, 2018 and December 31, 2017; Liquidation preference of $10,000 per share: 50,000 shares at March 31, 2018 and December 31, 2017	1,231,500	1,231,500
Common stock, $.50 par, 250,000,000 shares authorized, 159,768,397 shares issued at March 31, 2018; 159,817,518 shares issued at December 31, 2017	79,884	79,909
Common stock issuable, 24,371 shares at March 31, 2018; 27,138 shares at December 31, 2017	1,675	1,847
Additional paid-in capital	6,572,281	6,590,855
Retained earnings	10,404,458	10,164,804
Accumulated other comprehensive income (loss), net	(483,243)	(363,814)
Treasury stock — common, at cost — 12,993,850 shares at March 31, 2018; 9,733,115 shares at December 31, 2017	(2,096,861)	(1,454,282)
Total shareholders’ equity	15,709,694	16,250,819
Total liabilities and shareholders’ equity	$ 118,622,824	$ 118,593,487