CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest income:
Interest and fees on loans	$ 47,638	$ 42,297
Interest and dividends on taxable investments	14,275	12,229
Interest and dividends on nontaxable investments	5,598	5,761
Total interest income	67,511	60,287
Interest expense:
Interest on deposits	5,509	6,006
Interest on borrowings	7,400	7,291
Interest on subordinated debt held by unconsolidated subsidiary trusts	693	1,467
Total interest expense	13,602	14,764
Net interest income	53,909	45,523
Less: provision for loan losses	1,644	1,050
Net interest income after provision for loan losses	52,265	44,473
Noninterest income:
Deposit service fees	10,369	9,685
Other banking services	994	794
Benefit trust administration, consulting and actuarial fees	8,973	8,183
Wealth management services	3,132	2,180
Total noninterest income	23,468	20,842
Noninterest expenses:
Salaries and employee benefits	27,425	23,111
Occupancy and equipment	6,463	6,057
Data processing and communications	5,583	4,771
Amortization of intangible assets	1,086	901
Legal and professional fees	2,208	1,339
Office supplies and postage	1,468	1,196
Business development and marketing	1,172	1,254
FDIC insurance premiums	906	1,361
Acquisition expenses	260	691
Other	2,832	2,635
Total noninterest expenses	49,403	43,316
Income before income taxes	26,330	21,999
Income taxes	7,504	5,839
Net income	$ 18,826	$ 16,160
Basic earnings per share (in dollars per share)	$ 0.49	$ 0.48
Diluted earnings per share (in dollars per share)	$ 0.48	$ 0.48
Dividends declared per share (in dollars per share)	$ 0.26	$ 0.24