Investments - Summary of Unrealized Loss Positions (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) security	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) security	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) security
Investments in an unrealized loss position
Amount of pretax loss if securities in an unrealized loss position are sold	$ 527,000		$ 527,000
Available-for-sale Securities, Unrealized Loss Position
Less than 12 months, fair value	35,162,000		35,162,000
Less than 12 months, unrealized loss	(279,000)		(279,000)
12 months or more, fair value	17,733,000		17,733,000
12 months or more, unrealized loss	(248,000)		(248,000)
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	15,700,000	$ 1,400,000	55,191,000	$ 12,912,000
Gross gains on the sale of investments	479,000	4,000	1,100,000	125,000
Gross losses on the sale of investments	0	0	2,000	0
Held-to-maturity Securities
Sale of investment securities	$ 0	421,000	$ 0	$ 421,000
Gross gains on the sale of investments		5,000
Gross losses on the sale of investments		$ 0
U.S. Agency securities
Description and number of positions
Number of investments in an unrealized loss position, AFS | security	9		9		9
Available-for-sale Securities, Unrealized Loss Position
Less than 12 months, fair value	$ 10,990,000		$ 10,990,000		$ 28,351,000
Less than 12 months, unrealized loss	(92,000)		(92,000)		(181,000)
12 months or more, fair value	0		0		0
12 months or more, unrealized loss	$ 0		$ 0		$ 0
U.S. Sponsored Mortgage backed securities
Description and number of positions
Number of investments in an unrealized loss position, AFS | security	17		17		19
Available-for-sale Securities, Unrealized Loss Position
Less than 12 months, fair value	$ 13,130,000		$ 13,130,000		$ 20,647,000
Less than 12 months, unrealized loss	(62,000)		(62,000)		(233,000)
12 months or more, fair value	17,733,000		17,733,000		11,862,000
12 months or more, unrealized loss	$ (248,000)		$ (248,000)		$ (300,000)
Municipal Securities
Description and number of positions
Number of investments in an unrealized loss position, AFS | security	23		23
Number of investments in an unrealized loss position, HTM | security					22
Available-for-sale Securities, Unrealized Loss Position
Less than 12 months, fair value	$ 11,042,000		$ 11,042,000
Less than 12 months, unrealized loss	(125,000)		(125,000)
12 months or more, fair value	0		0
12 months or more, unrealized loss	$ 0		$ 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	0		0		1
Available-for-sale Securities, Unrealized Loss Position
Less than 12 months, fair value	$ 0		$ 0		$ 2,489,000
Less than 12 months, unrealized loss	0		0		(11,000)
12 months or more, fair value	0		0		0
12 months or more, unrealized loss	$ 0		$ 0		$ 0