Assets and Liabilities Measured at Fair Value - Level 3 fair value measurements for fair value on recurring basis (Details 2) - Recurring - Level 3 - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets	$ 10,465	$ 13,880
Liabilities, fair value	9,615	15,794
Derivative assets - mortgage
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets	$ 1,072	$ 188
Derivative assets - mortgage | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
ValuationTechnique	Internal model	Internal model
Unobservable Inputs	Pull through rate	Pull through rate
Pull through rate	75.90%	85.00%
Derivative assets - other
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets	$ 3,793	$ 9,230
ValuationTechnique	Dealer priced	Dealer priced
Unobservable Inputs	Dealer priced	Dealer priced
Derivative liabilities - risk participations
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Liabilities, fair value	$ 38
Derivative liabilities - risk participations | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
ValuationTechnique	Internal model	Internal model
Probable exposure rate	0.25%
Probability of default rate	1.80%
Derivative liabilities - other
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Liabilities, fair value	$ 9,577	$ 15,794
ValuationTechnique	Dealer priced	Dealer priced
Unobservable Inputs	Dealer priced	Dealer priced
Servicing rights for government guaranteed loans
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets	$ 5,100	$ 3,712
Servicing rights for government guaranteed loans | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
ValuationTechnique	Discounted cash flow	Discounted cash flow
Discount rate	12.10%	11.80%
Prepayment Rate	7.22%	6.95%
Corporate bonds
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets	$ 500	$ 750
ValuationTechnique	Indicative bid provided by a broker	Indicative bid provided by a broker
Unobservable Inputs	Multiple factors, including but not limited to, current operations, financial condition, cash flows, and recently executed financing transactions related to the company	Multiple factors, including but not limited to, current operations, financial condition, cash flows, and recently executed financing transactions related to the company