3. FAIR VALUE MEASUREMENTS - Assets and liabilities measured at fair value on a recurring and non-recurring basis (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Recurring
Impaired loans:
Total gain (losses)
Non Recurring
Impaired loans:
Total gain (losses)	80	(244)
US Government Agencies and Sponsored Agencies
Impaired loans:
Total gain (losses)
Corporate Debt Securities
Impaired loans:
Total gain (losses)
Obligations of states and political subdivisions
Impaired loans:
Total gain (losses)
Corporate stock
Impaired loans:
Total gain (losses)
Estimated Fair Value
Available-for-sale securities:
Asset fair value disclosure recurring	289,064	272,791
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	5,356	6,927
Level 1
Available-for-sale securities:
Asset fair value disclosure recurring	28	70
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 2
Available-for-sale securities:
Asset fair value disclosure recurring	289,036	272,721
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 3
Available-for-sale securities:
Asset fair value disclosure recurring
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	5,356	6,927
Commercial
Impaired loans:
Total gain (losses)	14
Real estate-commercial
Impaired loans:
Total gain (losses)		6
Other real estate owned
Impaired loans:
Total gain (losses)	66	(250)
Fair Value | US Government Agencies and Sponsored Agencies
Available-for-sale securities:
Asset fair value disclosure recurring	261,115	244,160
Fair Value | Corporate Debt Securities
Available-for-sale securities:
Asset fair value disclosure recurring	1,583	1,609
Fair Value | Obligations of states and political subdivisions
Available-for-sale securities:
Asset fair value disclosure recurring	26,289	26,903
Fair Value | Corporate stock
Available-for-sale securities:
Asset fair value disclosure recurring	77	119
Fair Value | Commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	666
Fair Value | Real estate-commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	286	306
Fair Value | Other real estate owned
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	4,404	6,621
Level 1 | US Government Agencies and Sponsored Agencies
Available-for-sale securities:
Asset fair value disclosure recurring
Level 1 | Corporate Debt Securities
Available-for-sale securities:
Asset fair value disclosure recurring
Level 1 | Obligations of states and political subdivisions
Available-for-sale securities:
Asset fair value disclosure recurring
Level 1 | Corporate stock
Available-for-sale securities:
Asset fair value disclosure recurring	28	70
Level 1 | Commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 1 | Real estate-commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 1 | Other real estate owned
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 2 | US Government Agencies and Sponsored Agencies
Available-for-sale securities:
Asset fair value disclosure recurring	261,115	244,160
Level 2 | Corporate Debt Securities
Available-for-sale securities:
Asset fair value disclosure recurring	1,583	1,609
Level 2 | Obligations of states and political subdivisions
Available-for-sale securities:
Asset fair value disclosure recurring	26,289	26,903
Level 2 | Corporate stock
Available-for-sale securities:
Asset fair value disclosure recurring	49	49
Level 2 | Commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 2 | Real estate-commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 2 | Other real estate owned
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring
Level 3 | US Government Agencies and Sponsored Agencies
Available-for-sale securities:
Asset fair value disclosure recurring
Level 3 | Corporate Debt Securities
Available-for-sale securities:
Asset fair value disclosure recurring
Level 3 | Obligations of states and political subdivisions
Available-for-sale securities:
Asset fair value disclosure recurring
Level 3 | Corporate stock
Available-for-sale securities:
Asset fair value disclosure recurring
Level 3 | Commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	666
Level 3 | Real estate-commercial
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	286	306
Level 3 | Other real estate owned
Impaired loans:
Assets, Fair Value Disclosure, Nonrecurring	$ 4,404	$ 6,621