Fair Value Measurements (Details 2) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Investments in securities that are classified as level 3
Available-for-sale Securities	$ 365,792	$ 348,554
Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Weighted Average [Member]
Investments in securities that are classified as level 3
Cumulative Prepayment	2.50%	7.00%
Cumulative Default	14.80%	13.90%
Loss Given Default	94.20%	96.10%
Cure Given Default	63.80%	46.70%
Pooled trust preferred securities | Significant Unobservable Inputs (Level 3)
Investments in securities that are classified as level 3
Available-for-sale Securities	$ 1,586	$ 6,321
Pooled trust preferred securities | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Minimum [Member]
Investments in securities that are classified as level 3
Cumulative Prepayment	0.00%	0.00%
Cumulative Default	5.00%	3.00%
Loss Given Default	85.00%	85.00%
Cure Given Default	0.00%	0.00%
Pooled trust preferred securities | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Maximum [Member]
Investments in securities that are classified as level 3
Cumulative Prepayment	65.00%	75.00%
Cumulative Default	100.00%	100.00%
Loss Given Default	100.00%	100.00%
Cure Given Default	75.00%	75.00%
Impaired loans | Significant Unobservable Inputs (Level 3)
Investments in securities that are classified as level 3
Fair Value	$ 6,011	$ 8,196
Other real estate owned and other foreclosed assets | Significant Unobservable Inputs (Level 3)
Investments in securities that are classified as level 3
Fair Value	$ 2,532	$ 7,743