Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
ASSETS
Cash and due from banks	$ 331,049	$ 380,799	$ 426,247
Interest-bearing deposits in banks	428,848	83,018	106,178
Total cash and cash equivalents	759,897	463,817	532,425
Investment securities:
Held-to-maturity	2,613,700	2,674,093	2,855,174
Available-for-sale	4,104,214	3,967,735	3,791,059
Other investments	148,159	148,172	148,475
Loans held for sale	5,249	5,472	3,568
Loans	16,225,450	16,076,945	15,490,889
Allowance for loan losses	(151,937)	(153,691)	(146,552)
Net loans	16,073,513	15,923,254	15,344,337
Premises and equipment, net	305,764	319,488	320,392
Goodwill	741,740	741,740	741,740
Intangible assets	58,324	60,628	68,422
Covered other real estate	783	2,134	40,231
Accrued interest receivable and other assets	1,251,306	1,218,071	1,272,297
Total assets	26,062,649	25,524,604	25,118,120
Deposits:
Noninterest-bearing	6,055,569	5,942,248	5,666,752
Interest-bearing	3,641,216	3,476,729	3,277,118
Savings and money market accounts	9,231,829	8,450,123	8,610,553
Certificates and other time deposits	2,172,752	2,238,903	2,371,172
Total deposits	21,101,366	20,108,003	19,925,595
Federal funds purchased and securities sold under agreements to repurchase	719,850	1,037,075	1,113,371
Wholesale borrowings	378,996	580,648	316,628
Long-term debt	519,249	505,173	512,625
Accrued taxes, expenses and other liabilities	345,231	353,610	361,115
Total liabilities	23,064,692	22,584,509	22,229,334
Shareholders' equity:
5.875% Non-Cumulative Perpetual Preferred Stock, Series A, without par value: authorized 115,000 shares; 100,000 issued	100,000	100,000	100,000
Common Stock warrant	0	0	3,000
Common Stock, without par value; authorized 300,000,000 shares; issued: March 31, 2016, December 31, 2015 and March 31, 2015 - 170,183,515 shares	127,937	127,937	127,937
Capital surplus	1,390,516	1,386,677	1,394,933
Accumulated other comprehensive loss	(48,341)	(79,274)	(49,267)
Retained earnings	1,543,976	1,519,438	1,433,926
Treasury stock, at cost: March 31, 2016 - 4,463,581; December 31, 2015 - 4,425,927; March 31, 2015 - 4,730,374 shares	(116,131)	(114,683)	(121,743)
Total shareholders' equity	2,997,957	2,940,095	2,888,786
Total liabilities and shareholders' equity	$ 26,062,649	$ 25,524,604	$ 25,118,120