INVESTMENT SECURITIES - Summary of Unrealized Loss Positions (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) security	Dec. 31, 2015 USD ($) security	Dec. 31, 2014 USD ($)
Investments in an unrealized loss position
Amount of pretax loss if securities in an unrealized loss position are sold	$ 3,800,000
Available-for sale Securities, Unrealized Loss Position
Less than 12 months, fair value	104,750,000
Less than 12 months, unrealized loss	(3,488,000)
12 months or more, fair value	13,919,000
12 months or more, unrealized loss	(322,000)
Available-for-sale and Held-to-Maturity Securities, Unrealized Loss Position
Less than 12 months, fair value		$ 55,314,000
Less than 12 months, unrealized loss		(457,000)
12 months or more, fair value		17,421,000
12 months or more, unrealized loss		(356,000)
Available-for-sale Securities
Sales of investment securities	55,191,000	12,912,000	$ 61,299,000
Gains on the sale of investments	1,100,000	125,000	553,000
Losses on the sale of investments	2,000	0	140,000
Held-to-maturity Securities
Sales of investment securities	$ 0	421,000	$ 0
Gains on the sale of held-to-maturity securities		$ 5,000
U. S. Agency securities
Description and Number of Positions
Number of investments in an unrealized loss position, AFS | security	16	9
Available-for sale Securities, Unrealized Loss Position
Less than 12 months, fair value	$ 28,814,000	$ 28,351,000
Less than 12 months, unrealized loss	(425,000)	(181,000)
12 months or more, fair value	0	0
12 months or more, unrealized loss	$ 0	$ 0
U.S. Sponsored Mortgage-backed securities
Description and Number of Positions
Number of investments in an unrealized loss position, AFS | security	29	19
Available-for sale Securities, Unrealized Loss Position
Less than 12 months, fair value	$ 33,209,000	$ 20,647,000
Less than 12 months, unrealized loss	(1,040,000)	(233,000)
12 months or more, fair value	13,919,000	11,862,000
12 months or more, unrealized loss	$ (322,000)	$ (300,000)
Municipal securities
Description and Number of Positions
Number of investments in an unrealized loss position, AFS | security	86
Number of investments in an unrealized loss position, HTM | security		22
Available-for sale Securities, Unrealized Loss Position
Less than 12 months, fair value	$ 42,727,000
Less than 12 months, unrealized loss	(2,023,000)
12 months or more, fair value	0
12 months or more, unrealized loss	$ 0
Held-to-maturity Securities, Unrealized Loss Position
Less than 12 months, fair value		$ 3,827,000
Less than 12 months, unrealized loss		(32,000)
12 months or more, fair value		5,559,000
12 months or more, unrealized loss		$ (56,000)
Equity and other securities
Description and Number of Positions
Number of investments in an unrealized loss position, AFS | security		1
Available-for sale Securities, Unrealized Loss Position
Less than 12 months, fair value		$ 2,489,000
Less than 12 months, unrealized loss		(11,000)
12 months or more, fair value		0
12 months or more, unrealized loss		$ 0