Fair Value (Details 2) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Fair Value
Other Real Estate	$ 31,378	$ 51,250	$ 42,726	$ 64,918
Nonrecurring basis | OREO
Fair Value
Other Real Estate	31,378	51,250	42,726
Nonrecurring basis | Non-acquired impaired loans
Fair Value
Other Real Estate	12,123	10,655	12,612
Nonrecurring basis | Significant Unobservable Inputs (Level 3) | OREO
Fair Value
Other Real Estate	31,378	51,250	42,726
Nonrecurring basis | Significant Unobservable Inputs (Level 3) | Non-acquired impaired loans
Fair Value
Other Real Estate	$ 12,123	$ 10,655	$ 12,612
Nonrecurring basis | Significant Unobservable Inputs (Level 3) | Discounted appraisals | Impaired loans
Quantitative Information about Level 3 Fair Value Measurements
Collateral discounts (as a percent)	4.42%		5.80%
Nonrecurring basis | Significant Unobservable Inputs (Level 3) | Discounted appraisals | Impaired loans | Weighted average
Quantitative Information about Level 3 Fair Value Measurements
Collateral discounts (as a percent)		4.91%
Nonrecurring basis | Significant Unobservable Inputs (Level 3) | Discounted appraisals | OREO
Quantitative Information about Level 3 Fair Value Measurements
Collateral discounts and estimated costs to sell (as a percent)	19.49%		21.89%
Nonrecurring basis | Significant Unobservable Inputs (Level 3) | Discounted appraisals | OREO | Weighted average
Quantitative Information about Level 3 Fair Value Measurements
Collateral discounts and estimated costs to sell (as a percent)		27.46%