Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INTEREST AND DIVIDEND INCOME
Loans, including fees	$ 226,993	$ 203,993	$ 172,182
Interest and dividends on securities:
Taxable	38,490	39,314	29,233
Tax-exempt	18,390	16,764	13,589
Total interest and dividends on securities	56,880	56,078	42,822
Other interest income	2,224	1,641	987
Total interest and dividend income	286,097	261,712	215,991
INTEREST EXPENSE
Interest bearing demand deposits	2,817	1,943	1,568
Money market deposits	1,860	1,914	1,877
Savings deposits	696	640	532
Certificates of deposit	10,419	11,033	13,286
Total interest expense on deposits	15,792	15,530	17,263
Federal Home Loan Bank borrowings	11,985	5,510	968
Other short-term borrowings	478	370	1,333
Subordinated debt and junior subordinated debt	4,512	3,315	3,199
Total interest expense	32,767	24,725	22,763
NET INTEREST INCOME	253,330	236,987	193,228
Provision for credit losses	8,478	8,353	6,405
Net interest income after provision for credit losses	244,852	228,634	186,823
NON-INTEREST INCOME
Trust fees	21,630	21,900	21,069
Service charges on deposits	18,333	16,743	16,135
Electronic banking fees	15,596	14,361	12,708
Net securities brokerage revenue	6,449	7,692	6,922
Bank-owned life insurance	4,064	4,863	4,614
Net gains on sales of mortgage loans	2,529	2,071	1,604
Net securities gains	2,357	948	903
Net gain / (loss) on other real estate owned and other assets	790	356	(1,006)
Other income	9,751	5,532	5,555
Total non-interest income	81,499	74,466	68,504
NON-INTEREST EXPENSE
Salaries and wages	84,281	77,340	67,408
Employee benefits	27,952	26,896	21,518
Net occupancy	14,664	13,635	12,122
Equipment	14,543	13,194	11,542
Marketing	5,391	5,646	5,242
FDIC insurance	3,990	4,107	3,376
Amortization of intangible assets	3,598	3,136	1,920
Restructuring and merger-related expense	13,261	11,082	1,309
Other operating expenses	41,000	38,887	37,196
Total non-interest expense	208,680	193,923	161,633
Income before provision for income taxes	117,671	109,177	93,694
Provision for income taxes	31,036	28,415	23,720
NET INCOME	$ 86,635	$ 80,762	$ 69,974
EARNINGS PER COMMON SHARE
Basic	$ 2.16	$ 2.15	$ 2.39
Diluted	$ 2.16	$ 2.15	$ 2.39
AVERAGE COMMON SHARES OUTSTANDING
Basic	40,100,320	37,488,331	29,249,499
Diluted	40,127,076	37,547,127	29,333,876
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.96	$ 0.92	$ 0.88