SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business and Organization [Abstract]
Number of full service banking offices									17
Operating Segments [Abstract]
Number of operating segments									1
Cash and Cash Equivalents [Abstract]
Interest-earning deposits maturity, Maximum for inclusion as cash equivalents									90 days
Investment Securities [Abstract]
Number of classifications of investment securities	3								3
Held-to-maturity securities	$ 0				$ 0				$ 0	$ 0
Trading securities	0				0				0	0
Number of years significantly below cost to recognize an impairment									1 year
Allowance for Loan Losses [Abstract]
Size of family properties, minimum									1
Size of family properties, maximum									4
Number of days past for loan to be considered impaired, Maximum									90 days
Goodwill [Abstract]
Goodwill impairment loss									0	0	0
Derivative Financial Instruments [Abstract]
Net gain or loss recognized in earnings									0	0	0
Computation of earnings per share [Abstract]
Net income applicable to common stock	$ 3,549,000	$ 3,464,000	$ 3,753,000	$ 3,449,000	$ 3,477,000	$ 3,378,000	$ 3,147,000	$ 2,830,000	$ 14,215,000	$ 12,832,000	$ 11,502,000
Basic earnings per share computation: [Abstract]
Weighted average common shares outstanding (in shares)									2,911,885	2,943,028	2,952,041
Earnings per share - basic (in dollars per share)	$ 1.22	$ 1.19	$ 1.29	$ 1.18	$ 1.18	$ 1.15	$ 1.07	$ 0.96	$ 4.88	$ 4.36	$ 3.90
Diluted earnings per share computation: [Abstract]
Weighted average common shares outstanding for basic earnings per share (in shares)									2,911,885	2,943,028	2,952,041
Add: Dilutive effects of restricted stock (in shares)									1,642	0	0
Weighted average common shares outstanding for dilutive earnings per share (in shares)									2,913,527	2,943,028	2,952,041
Earnings per share - dilutive (in dollars per share)	$ 1.22	$ 1.19	$ 1.29	$ 1.18	$ 1.18	$ 1.15	$ 1.07	$ 0.96	$ 4.88	$ 4.36	$ 3.90
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive restricted stock excluded from net income per share calculations (in shares)									2,621	9,921	11,241
Minimum [Member]
Allowance for Loan Losses [Abstract]
Number of days past for loan to be considered impaired, Maximum									90 days
Minimum [Member] | Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life									3 years
Maximum [Member] | Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life									5 years 6 months
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Premises and Equipment [Line Items]
Useful life									3 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Premises and Equipment [Line Items]
Useful life									15 years
Building Premises [Member] | Minimum [Member]
Premises and Equipment [Line Items]
Useful life									5 years
Building Premises [Member] | Maximum [Member]
Premises and Equipment [Line Items]
Useful life									40 years
Open End Loans [Member]
Loans to be Charged Off [Line Items]
Number of days past due before charge-off									180 days
Closed End Loans [Member]
Loans to be Charged Off [Line Items]
Number of days past due before charge-off									120 days
All Other Loans [Member]
Loans to be Charged Off [Line Items]
Number of days past due before charge-off									90 days