Securities (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Gain on sale of investments	$ (10)	$ (10)	$ (13)	$ (14)
Gross unrealized losses	3,742		3,742			$ 6,719
Cumulative OTTI charges	13,974	$ 13,995	13,974	$ 13,995	$ 13,995	13,995	$ 13,995	$ 14,050
Amortized Cost	853,807		853,807			876,796
Securities available-for-sale	$ 876,538		$ 876,538			$ 891,082
Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Basis point spread on variable rate	1.60%		1.60%
Minimum [Member] | Standard Poors [Member]
Schedule of Available-for-sale Securities [Line Items]
Credit Quality Indicator Pricing	40.92		40.92
Minimum [Member] | Moody Investor Service [Member]
Schedule of Available-for-sale Securities [Line Items]
Credit Quality Indicator Pricing	13.05		13.05
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Basis point spread on variable rate	1.80%		1.80%
Maximum [Member] | Standard Poors [Member]
Schedule of Available-for-sale Securities [Line Items]
Credit Quality Indicator Pricing	45.47		45.47
Maximum [Member] | Moody Investor Service [Member]
Schedule of Available-for-sale Securities [Line Items]
Credit Quality Indicator Pricing	40.27		40.27