Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Interest income:
Loans, including fees	$ 63,534	$ 68,323
Investment securities:
Taxable	20,519	24,512
Tax-exempt	3,036	2,861
Other interest income	21	86
Total interest income	87,110	95,782
Interest expense:
Savings deposits	1,011	1,623
Time deposits	4,445	6,485
Securities sold under repurchase agreements	7,568	10,302
Other borrowings	290	208
Junior subordinated interest deferrable debentures	1,164	2,047
Total interest expense	14,478	20,665
Net interest income	72,632	75,117
Provision for probable loan losses	7,419	5,285
Net interest income after provision for probable loan losses	65,213	69,832
Non-interest income:
Service charges on deposit accounts	23,830	22,753
Other service charges, commissions and fees
Banking	9,983	10,064
Non-banking	1,061	1,251
Investment securities transactions, net	9,601	1,172
Other investments, net	6,997	5,134
Other income	1,780	2,803
Total non-interest income	53,252	43,177
Non-interest expense:
Employee compensation and benefits	30,211	29,401
Occupancy	7,812	8,734
Depreciation of bank premises and equipment	6,625	6,927
Professional fees	3,723	3,370
Deposit insurance assessments	1,616	1,567
Net expense, other real estate owned	1,789	1,181
Amortization of identified intangible assets	1,137	1,137
Advertising	1,846	1,827
Early termination fee - securities sold under repurchase agreements	9,885
Impairment charges (Total other-than-temporary impairment charges, $968 net of $658, and $1,650, net of $1,464, included in other comprehensive income)	310	186
Other	15,907	13,813
Total non-interest expense	80,861	68,143
Income before income taxes	37,604	44,866
Provision for income taxes	9,535	13,179
Net income	28,069	31,687
Preferred stock dividends		3,343
Net income available to common shareholders	$ 28,069	$ 28,344
Basic earnings per common share:
Weighted average number of shares outstanding: (in shares)	67,187,583	67,271,146
Net income (in dollars per share)	$ 0.42	$ 0.42
Fully diluted earnings per common share:
Weighted average number of shares outstanding: (in shares)	67,279,981	67,355,427
Net income (in dollars per share)	$ 0.42	$ 0.42