Investment Securities - Narrative (Details)	3 Months Ended
	Mar. 31, 2017 USD ($) security	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Investments, Debt and Equity Securities [Abstract]
Carrying value of securities pledged as collateral	$ 551,860,000		$ 572,896,000
Book value of securities sold under agreements to repurchase	138,657,000		145,936,000
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Available-for-sale unrealized losses	7,102,000		9,674,000
Net realized gains on sales of available for sale securities	598,000	$ 997,000
Held-to-maturity unrealized losses	3,375,000		3,802,000
State and municipal
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Available-for-sale unrealized losses	$ 4,153,000		5,564,000
Available-for-sale, number of securities in unrealized loss positions | security	83
Held-to-maturity unrealized losses	$ 1,386,000		1,796,000
Held-to-maturity, number of securities in unrealized loss positions | security	51
U.S. Government-sponsored mortgage-backed securities
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Available-for-sale unrealized losses	$ 2,949,000		3,071,000
Available-for-sale, number of securities in unrealized loss positions | security	45
Held-to-maturity unrealized losses	$ 1,531,000		1,527,000
Held-to-maturity, number of securities in unrealized loss positions | security	31
U.S. Government-sponsored agency securities
Schedule of Available for sale Securities and Held to maturity Securities [Line Items]
Available-for-sale unrealized losses	$ 0
Available-for-sale, number of securities in unrealized loss positions | security	0
Held-to-maturity unrealized losses	$ 458,000		$ 479,000
Held-to-maturity, number of securities in unrealized loss positions | security	5