Fair Value Measurements - (Details 7) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financial assets
Securities held to maturity	$ 439,070	$ 430,163
Securities available for sale	526,220	553,584
Mortgage loans held for sale	108,023	25,628
Loans covered under loss-share agreements	121,626	143,041
FDIC loss-share indemnification asset	6,659	12,516
Mortgage servicing rights	12,920	11,662
Level 1
Financial assets
Cash and cash equivalents	154,962	161,583
Securities held to maturity	0	0
Securities available for sale	0	0
Mortgage loans held for sale	0	0
Loans covered under loss-share agreements	0	0
Loans not covered under loss-share agreements, net	0	0
FDIC loss-share indemnification asset	0	0
Mortgage servicing rights	0	0
Derivative instruments	0	0
Financial liabilities
Deposits	3,339,035	3,532,266
Short-term borrowings	64,229	32,403
Federal Home Loan Bank advances	0	0
Junior subordinated debentures	0	0
Derivative instruments	0	0
Level 2
Financial assets
Cash and cash equivalents	0	0
Securities held to maturity	447,660	442,488
Securities available for sale	507,093	533,828
Mortgage loans held for sale	108,023	25,628
Loans covered under loss-share agreements	0	0
Loans not covered under loss-share agreements, net	0	0
FDIC loss-share indemnification asset	0	0
Mortgage servicing rights	0	0
Derivative instruments	6,736	3,731
Financial liabilities
Deposits	1,177,938	1,309,421
Short-term borrowings	0	0
Federal Home Loan Bank advances	63,821	92,532
Junior subordinated debentures	80,971	80,971
Derivative instruments	5,814	6,293
Level 3
Financial assets
Cash and cash equivalents	0	0
Securities held to maturity	0	0
Securities available for sale	19,127	19,756
Mortgage loans held for sale	0	0
Loans covered under loss-share agreements	122,120	143,487
Loans not covered under loss-share agreements, net	3,828,476	3,751,727
FDIC loss-share indemnification asset	6,659	12,516
Mortgage servicing rights	14,457	12,378
Derivative instruments	0	0
Financial liabilities
Deposits	0	0
Short-term borrowings	0	0
Federal Home Loan Bank advances	0	0
Junior subordinated debentures	0	0
Derivative instruments	0	0
Carrying Value
Financial assets
Cash and cash equivalents	154,962	161,583
Securities held to maturity	439,070	430,163
Securities available for sale	526,220	553,584
Mortgage loans held for sale	108,023	25,628
Loans covered under loss-share agreements	121,626	143,041
Loans not covered under loss-share agreements, net	3,873,690	3,844,833
FDIC loss-share indemnification asset	6,659	12,516
Mortgage servicing rights	12,920	11,662
Derivative instruments	6,736	3,731
Financial liabilities
Deposits	4,890,444	4,838,418
Short-term borrowings	64,229	32,403
Federal Home Loan Bank advances	59,824	61,611
Junior subordinated debentures	94,821	94,574
Derivative instruments	5,814	6,293
Fair Value
Financial assets
Cash and cash equivalents	154,962	161,583
Securities held to maturity	447,660	442,488
Securities available for sale	526,220	553,584
Mortgage loans held for sale	108,023	25,628
Loans covered under loss-share agreements	122,120	143,487
Loans not covered under loss-share agreements, net	3,828,476	3,751,727
FDIC loss-share indemnification asset	6,659	12,516
Mortgage servicing rights	14,457	12,378
Derivative instruments	6,736	3,731
Financial liabilities
Deposits	4,516,973	4,841,687
Short-term borrowings	64,229	32,403
Federal Home Loan Bank advances	63,821	92,532
Junior subordinated debentures	80,971	80,971
Derivative instruments	$ 5,814	$ 6,293