Investment Securities - Narrative (Details)	9 Months Ended
	Sep. 30, 2017 USD ($) security	Sep. 30, 2016 USD ($) security	Dec. 31, 2016 USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of private-label collateralized mortgage obligations | security	1
Combined balance of private-label collateralized mortgage obligations	$ 8,000
AFS and HTM securities in unrealized loss positions qualitative disclosure number of positions | security	51
Unrealized losses as a percentage of individual securities amortized cost basis	1.29%
Unrealized losses as percentage of Company's total amortized cost basis	0.65%
Number of securities in an unrealized loss position for over 12 months | security	18
Amortized cost basis of securities in a continuous loss position	$ 59,000,000
Unrealized loss on securities in a continuous loss position	1,200,000
Impairment related to credit quality	$ 0
Number of Available for sale Securities Sold | security	16
Number Of Held to Maturity Securities Sold | security	1
Available-for-sale securities, realized gain (loss)	$ 340,000
Held-to-maturity Securities, Sold Security, Realized Gain (Loss)	$ 7,000
Number of available-for-sale securities sold with gains | security	13	2
Available-for-sale securities, gross realized gains	$ 449,000	$ 20,000
Number of available-for-sale securities sold with losses | security	3
Available-for-sale securities, gross realized losses	$ 109,000
Securities pledged as collateral for public funding	$ 236,300,000		$ 293,400,000