CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Interest income:
Interest and fees on loans	$ 48,590	$ 50,702	$ 143,305	$ 142,470
Interest and dividends on taxable investments	16,762	14,278	48,487	41,147
Interest and dividends on nontaxable investments	6,042	5,438	17,658	16,938
Total interest income	71,394	70,418	209,450	200,555
Interest expense:
Interest on deposits	4,402	6,887	14,291	19,684
Interest on borrowings	7,535	7,466	22,648	22,146
Interest on subordinated debt held by unconsolidated subsidiary trusts	682	1,497	2,056	4,447
Total interest expense	12,619	15,850	38,995	46,277
Net interest income	58,775	54,568	170,455	154,278
Less: provision for loan losses	2,643	1,043	6,442	3,143
Net interest income after provision for loan losses	56,132	53,525	164,013	151,135
Noninterest income:
Deposit service fees	12,057	11,134	33,461	31,307
Mortgage and other banking services	1,405	1,499	3,295	3,920
Benefit trust administration, consulting and actuarial fees	8,912	7,685	26,549	23,722
Wealth management services	3,194	2,904	9,427	7,866
Gain (loss) on investment securities and debt extinguishments, net	291	(6)	291	8
Total noninterest income	25,859	23,216	73,023	66,823
Operating expenses:
Salaries and employee benefits	28,126	26,543	82,395	75,185
Occupancy and equipment	6,541	6,103	19,134	18,413
Data processing and communications	6,078	5,330	17,429	15,278
Amortization of intangible assets	1,212	1,161	3,343	3,251
Legal and professional fees	1,710	1,640	5,723	4,286
Office supplies and postage	1,345	1,300	4,195	3,873
Business development and marketing	1,312	1,096	4,360	4,534
FDIC insurance premiums	919	544	2,728	3,082
Acquisition expenses	4,796	381	5,221	4,689
Other	4,046	3,995	10,330	9,944
Total operating expenses	56,085	48,093	154,858	142,535
Income before income taxes	25,906	28,648	82,178	75,423
Income taxes	7,539	8,640	23,914	21,269
Net income	$ 18,367	$ 20,008	$ 58,264	$ 54,154
Basic earnings per share (in dollars per share)	$ 0.46	$ 0.54	$ 1.48	$ 1.52
Diluted earnings per share (in dollars per share)	$ 0.46	$ 0.54	$ 1.46	$ 1.50
Dividends declared per share (in dollars per share)	$ 0.27	$ 0.26	$ 0.79	$ 0.74