Fair Value Measurements (Details 7) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair values of defined benefit pension plan assets by category of the firm
Securities held to maturity	$ 458,400	$ 430,163
Securities available for sale, at fair value	646,805	553,584
Mortgage loans held for sale	225,254	25,628
Loans covered under loss-share agreements	93,142	143,041
Loans not covered under loss-share agreements, net	3,830,434	3,267,486
FDIC loss-share indemnification asset	7,149	12,516	$ 26,273
Financial liabilities
Federal Home Loan Bank advances		92,532
Quoted Prices In Active Markets for Identical Assets (Level 1)
Fair values of defined benefit pension plan assets by category of the firm
Cash and cash equivalents	211,571	161,583
Securities held to maturity	0	0
Securities available for sale, at fair value	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	4,723,312	3,532,266
Short-term borrowings	422,279	32,403
Other long-term borrowings	192	237
Federal Home Loan Bank advances	0	0
Junior subordinated debentures	0	0
Derivative instruments	0	0
Significant Other Observable Inputs (Level 2)
Fair values of defined benefit pension plan assets by category of the firm
Cash and cash equivalents	0	0
Securities held to maturity	473,753	442,488
Securities available for sale, at fair value	627,336	533,828
Mortgage loans held for sale	225,254	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	7,498	3,731
Financial liabilities
Deposits	1,502,202	1,309,421
Short-term borrowings	0	0
Other long-term borrowings	0	0
Federal Home Loan Bank advances	56,101	92,532
Junior subordinated debentures	78,095	80,971
Derivative instruments	7,319	6,293
Significant Unobservable Inputs (Level 3)
Fair values of defined benefit pension plan assets by category of the firm
Cash and cash equivalents	0	0
Securities held to maturity	0	0
Securities available for sale, at fair value	19,469	19,756
Mortgage loans held for sale	0	0
Loans covered under loss-share agreements	92,528	143,487
Loans not covered under loss-share agreements, net	5,208,630	3,751,727
FDIC loss-share indemnification asset	7,149	12,516
Mortgage servicing rights	33,283	12,378
Derivative instruments	0	0
Financial liabilities
Deposits	0	0
Short-term borrowings	0	0
Other long-term borrowings	0	0
Federal Home Loan Bank advances	0	0
Junior subordinated debentures	0	0
Derivative instruments	0	0
Carrying Value
Fair values of defined benefit pension plan assets by category of the firm
Cash and cash equivalents	211,571	161,583
Securities held to maturity	458,400	430,163
Securities available for sale, at fair value	646,805	553,584
Mortgage loans held for sale	225,254	25,628
Loans covered under loss-share agreements	93,142	143,041
Loans not covered under loss-share agreements, net	5,277,883	3,844,833
FDIC loss-share indemnification asset	7,149	12,516
Mortgage servicing rights	29,642	11,662
Derivative instruments	7,498	3,731
Financial liabilities
Deposits	6,218,602	4,838,418
Short-term borrowings	422,279	32,403
Other long-term borrowings	192	237
Federal Home Loan Bank advances	52,930	61,611
Junior subordinated debentures	95,095	94,574
Derivative instruments	7,319	6,293
Fair Value
Fair values of defined benefit pension plan assets by category of the firm
Cash and cash equivalents	211,571	161,583
Securities held to maturity	473,753	442,488
Securities available for sale, at fair value	646,805	553,584
Mortgage loans held for sale	225,254	25,628
Loans covered under loss-share agreements	92,528	143,487
Loans not covered under loss-share agreements, net	5,208,630	3,751,727
FDIC loss-share indemnification asset	7,149	12,516
Mortgage servicing rights	33,283	12,378
Derivative instruments	7,498	3,731
Financial liabilities
Deposits	6,225,514	4,841,687
Short-term borrowings	422,279	32,403
Other long-term borrowings	192	237
Federal Home Loan Bank advances	56,101
Junior subordinated debentures	78,095	80,971
Derivative instruments	$ 7,319	$ 6,293