Consolidated Statements of Condition (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 234,959	$ 283,100
Investment securities:
Held-to-maturity (Market value of $2,400 on March 31, 2013 and $2,400 on December 31, 2012)	2,400	2,400
Available-for-sale (Amortized cost of $5,102,700 on March 31, 2013 and $5,423,189 on December 31, 2012)	5,180,274	5,525,015
Total investment securities	5,182,674	5,527,415
Loans	4,826,509	4,775,004
Less allowance for probable loan losses	(62,968)	(58,193)
Net loans	4,763,541	4,716,811
Bank premises and equipment, net	480,828	481,287
Accrued interest receivable	28,384	31,034
Other investments	368,075	372,739
Identified intangible assets, net	6,682	7,819
Goodwill	282,532	282,532
Other assets	172,497	179,936
Total assets	11,520,172	11,882,673
Deposits:
Demand - non-interest bearing	2,612,327	2,465,750
Savings and interest bearing demand	2,868,564	2,867,151
Time	2,835,652	2,954,312
Total deposits	8,316,543	8,287,213
Securities sold under repurchase agreements	1,055,587	1,129,679
Other borrowed funds	387,493	749,027
Junior subordinated deferrable interest debentures	190,726	190,726
Other liabilities	134,949	90,320
Total liabilities	10,085,298	10,446,965
Commitments, Contingent Liabilities and Other Tax Matters (Note 10)
Shareholders' equity:
Common shares of $1.00 par value. Authorized 275,000,000 shares; issued 95,725,560 shares on March 31, 2013 and 95,724,517 shares on December 31, 2012	95,726	95,725
Surplus	163,413	163,287
Retained earnings	1,384,173	1,369,543
Accumulated other comprehensive income (including $(7,234) and $(6,811) of comprehensive loss related to other-than- temporary impairment for non-credit related issues)	50,071	65,662
Total shareholders' equity before treasury stock	1,693,383	1,694,217
Less cost of shares in treasury, 28,537,180 shares on March 31, 2013 and 28,537,180 December 31, 2012	(258,509)	(258,509)
Total shareholders' equity	1,434,874	1,435,708
Total liabilities and shareholders' equity	$ 11,520,172	$ 11,882,673