Investment Securities - Narrative (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 ($)
Investments, Debt and Equity Securities [Abstract]
Net realized and unrealized gain (loss) on trading securities	$ 8,000	$ (33,000)	$ 54,000	$ (37,000)
Available for sale securities in unrealized loss, positions number of positions, less than twelve months | security	13		13
Available for sale securities in unrealized loss, positions number of positions, greater than twelve months | security	11		11
Proceeds from sales of available for sale securities			$ 42,180,000	43,051,000
Impairment charges	$ 0	$ 0	0	$ 0
Investment securities, carrying value	$ 102,872,000		$ 102,872,000		$ 131,089,000