SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended								12 Months Ended
	Jun. 30, 2009	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Interest income		$ 52,571	$ 51,027	$ 51,495	$ 50,820	$ 51,414	$ 48,555	$ 48,426	$ 47,796	$ 205,914		$ 196,192		$ 195,751
Interest expense		5,666	5,831	5,880	5,958	5,935	5,717	5,798	5,943	23,336		23,393		28,672
Net interest income		46,905	45,196	45,615	44,862	45,479	42,838	42,628	41,853	182,578		172,799		167,079
Provision		3,150	2,650	3,100	1,300	4,350	3,606	8,500	1,600	10,200		18,056		11,482
Other noninterest income		17,007	17,367	16,692	15,724	16,900	14,801	14,983	13,909
Net gain on securities	1,400									230		116		723
Gains (Losses) on Extinguishment of Debt		0	763	0	0	0	0	0	0	763		0		0
Gain on life insurance benefits		227					1,307
Total noninterest income		17,464	18,130	16,692	15,724	17,016	16,108	14,983	13,909	68,009		62,016		52,700
Other noninterest expenses		41,626	40,356	41,410	41,575	39,569	37,230	36,327	37,358	36,497		32,027		29,719
Prepayment fee on borrowings						7						(7)		(757)
Goodwill impairment							2,227				[1]	2,227	[1]		[1]
Merger and acquisition expenses		6,219	366	754	1,345	5,474	595	672		8,685		6,741
Total noninterest expenses		47,845	40,722	42,164	42,920	45,050	40,052	36,999	37,358	173,649		159,459		145,713
Provision for income taxes		2,786	5,299	4,285	4,114	3,127	3,687	3,238	4,621	16,484		14,673		17,148
Net income		$ 10,588	$ 14,655	$ 12,758	$ 12,252	$ 9,968	$ 11,601	$ 8,874	$ 12,183	$ 50,254		$ 42,627		$ 45,436
Basic earnings per share (in dollars per share)		$ 0.45	$ 0.64	$ 0.56	$ 0.54	$ 0.45	$ 0.54	$ 0.41	$ 0.57	$ 2.18		$ 1.96		$ 2.12
Diluted earnings per share (in dollars per share)		$ 0.45	$ 0.64	$ 0.56	$ 0.54	$ 0.45	$ 0.53	$ 0.41	$ 0.56	$ 2.18		$ 1.95		$ 2.12
Weighted average common shares (basic) (in shares)		23,383,608	22,946,308	22,888,155	22,823,753	22,286,841	21,654,188	21,623,827	21,561,006	23,011,814		21,782,499		21,422,757
Common share equivalents (in shares)		97,445	100,806	52,144	46,040	31,502	52,116	20,377	24,481	76,764		29,817		28,830
Weighted average common shares (diluted) (in shares)		23,481,053	23,047,114	22,940,299	22,869,793	22,318,343	21,706,304	21,644,204	21,585,487	23,088,578		21,812,316		21,451,587

[1] Amount represents the total amount of goodwill relating to Compass Exchange Advisors, LLC, which was acquired in January 2007.