Investment Securities (Details Textual)	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) Security Investment	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Security
Investments Debt And Equity Securities [Abstract]
Trading securities	$ 8,116,000		$ 8,134,000
Carrying value of investment securities for pledge	$ 110,100,000		$ 108,200,000
Investment securities with fair value less than amortized cost | Security	50		34
Impairment loss recognized through impairment assessment process	$ 0	$ 0
Non-accrual investment securities	$ 726,000		$ 778,000
Trust preferred securities in nonaccrual status | Investment	2
Estimated length of interest payment delays	10 years