Investment Securities - Narrative (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) security	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) security	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Investments, Debt and Equity Securities [Abstract]
Net realized and unrealized gain (loss) on trading securities	$ 6,000	$ (4,000)	$ 46,000	$ (4,000,000)
Available for sale securities in unrealized loss, positions number of positions, less than twelve months | security	7		7
Available for sale securities in unrealized loss, positions number of positions, greater than twelve months | security	17		17
Proceeds from sales of available for sale securities			$ 36,007,000	31,693,000
Impairment charges	$ 0	$ 0	0	$ 0
Investment securities, carrying value	$ 108,144,000		$ 108,144,000		$ 131,089,000