Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest Income
Interest and fees on loans	$ 271,772	$ 209,429	$ 195,590
Interest on investment securities:
Taxable	8,786	9,147	10,234
Tax-exempt	9,073	7,054	6,394
Dividends on nonmarketable equity securities	1,648	1,224	1,105
Interest on deposits with the Federal Reserve Bank and other banks	510	407	738
Total Interest Income	291,789	227,261	214,061
Interest Expense
Interest on deposits	15,406	14,254	16,883
Interest Expense, Short-term Borrowings	453	414	484
Interest Expense, Borrowings	1,922	42	47
Total Interest Expense	17,781	14,710	17,414
Net Interest Income	274,008	212,551	196,647
Provision for loan losses	6,500	6,100	11,000
Net Interest Income after Provision for Loan Losses	267,508	206,451	185,647
Noninterest Income
Service charges and fees on deposit accounts	25,481	22,414	21,939
Wealth management revenue	20,552	16,015	13,989
Other charges and fees for customer services	25,513	18,928	17,151
Mortgage banking revenue	6,133	5,041	5,336
Gain on sale of investment securities	630	0	1,133
Gain on sale of merchant card services	0	400	0
Other	1,907	697	861
Total Noninterest Income	80,216	63,095	60,409
Operating Expenses
Salaries, wages and employee benefits	127,920	102,557	96,419
Occupancy	18,213	15,842	13,934
Equipment and software	18,569	14,737	13,734
Business Combination, Acquisition Related Costs	7,804	6,388	0
Other	51,388	40,401	40,861
Total Operating Expenses	223,894	179,925	164,948
Income Before Income Taxes	123,830	89,621	81,108
Federal income tax expense	37,000	27,500	24,300
Net Income	$ 86,830	$ 62,121	$ 56,808
Net Income Per Common Share
Basic	$ 2.41	$ 1.98	$ 2.02
Diluted	2.39	1.97	2.00
Cash Dividends Declared Per Common Share	$ 1.00	$ 0.94	$ 0.87