Loans and Allowance for Loan and Lease Losses - TDRs (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) loan	Jun. 30, 2015 USD ($) item	Jun. 30, 2016 USD ($) loan item	Jun. 30, 2015 USD ($) item	Dec. 31, 2015 USD ($)
Troubled debt restructurings
Allowance for credit losses of receivables, identified as TDRs under the newly adopted provisions	$ 300		$ 300
Accruing loans that were classified as TDRs	10,030		10,030		$ 10,056
Non-Accruing loans that were classified as TDRs	6,031		6,031		6,203
Total loans classified as TDRs	$ 16,061		$ 16,061		16,259
Number of TDRs	5	14	14	25
Pre-Modification Outstanding Recorded Investment	$ 183	$ 3,412	$ 1,538	$ 5,652
Post-Modification Outstanding Recorded Investment	$ 183	$ 3,412	$ 1,538	$ 5,652
Minimum
Troubled debt restructurings
Period of maturity date extensions granted	6 years		6 years
Maximum
Troubled debt restructurings
Period of maturity date extensions granted	10 years		10 years
Non-PCI Loans
Troubled debt restructurings
Accruing loans that were classified as TDRs	$ 8,644		$ 8,644		8,619
Non-Accruing loans that were classified as TDRs	5,962		5,962		6,091
Total loans classified as TDRs	14,606		$ 14,606		14,710
Number of TDRs | item		9		20
Pre-Modification Outstanding Recorded Investment		$ 2,717		$ 4,957
Post-Modification Outstanding Recorded Investment		$ 2,717		$ 4,957
Troubled Debt Restructurings That Subsequently Defaulted
Number of TDRs | item			1	1
Recorded Investment			$ 80	$ 18
Non-PCI Loans | Real Estate Secured | Commercial real estate
Troubled debt restructurings
Accruing loans that were classified as TDRs	2,480		2,480		2,395
Non-Accruing loans that were classified as TDRs	123		123		435
Total loans classified as TDRs	2,603		2,603		2,830
Number of TDRs | item		1		4
Pre-Modification Outstanding Recorded Investment		$ 106		$ 670
Post-Modification Outstanding Recorded Investment		$ 106		$ 670
Non-PCI Loans | Real Estate Secured | Land
Troubled debt restructurings
Number of TDRs | item		1		1
Pre-Modification Outstanding Recorded Investment		$ 97		$ 97
Post-Modification Outstanding Recorded Investment		$ 97		$ 97
Non-PCI Loans | Real Estate Secured | Construction and land
Troubled debt restructurings
Accruing loans that were classified as TDRs	791		791		1,171
Non-Accruing loans that were classified as TDRs	3,836		3,836		3,968
Total loans classified as TDRs	4,627		4,627		5,139
Non-PCI Loans | Real Estate Secured | Residential 1 to 4 family
Troubled debt restructurings
Accruing loans that were classified as TDRs	274		274		613
Non-Accruing loans that were classified as TDRs					81
Total loans classified as TDRs	274		274		694
Number of TDRs | item		1		3
Pre-Modification Outstanding Recorded Investment		$ 90		$ 624
Post-Modification Outstanding Recorded Investment		$ 90		$ 624
Non-PCI Loans | Real Estate Secured | Farmland
Troubled debt restructurings
Accruing loans that were classified as TDRs	324		324		504
Non-Accruing loans that were classified as TDRs	77		77		82
Total loans classified as TDRs	401		$ 401		586
Number of TDRs | item		1		1
Pre-Modification Outstanding Recorded Investment		$ 498		$ 498
Post-Modification Outstanding Recorded Investment		$ 498		$ 498
Troubled Debt Restructurings That Subsequently Defaulted
Number of TDRs | item			1
Recorded Investment			$ 80
Non-PCI Loans | Commercial | Commercial and industrial
Troubled debt restructurings
Accruing loans that were classified as TDRs	3,297		3,297		2,698
Non-Accruing loans that were classified as TDRs	1,554		1,554		1,515
Total loans classified as TDRs	$ 4,851		$ 4,851		4,213
Number of TDRs	5	5	13	9
Pre-Modification Outstanding Recorded Investment	$ 183	$ 1,926	$ 1,528	$ 2,113
Post-Modification Outstanding Recorded Investment	183	$ 1,926	1,528	$ 2,113
Troubled Debt Restructurings That Subsequently Defaulted
Number of TDRs | item				1
Recorded Investment				$ 18
Non-PCI Loans | Commercial | Agriculture
Troubled debt restructurings
Accruing loans that were classified as TDRs	1,369		1,369		1,124
Non-Accruing loans that were classified as TDRs	363		363
Total loans classified as TDRs	1,732		$ 1,732		1,124
Number of TDRs			1	1
Pre-Modification Outstanding Recorded Investment			$ 10	$ 898
Post-Modification Outstanding Recorded Investment			10	$ 898
Non-PCI Loans | Consumer
Troubled debt restructurings
Accruing loans that were classified as TDRs	109		109		114
Non-Accruing loans that were classified as TDRs	9		9		10
Total loans classified as TDRs	118		118		124
Number of TDRs | item				1
Pre-Modification Outstanding Recorded Investment				$ 57
Post-Modification Outstanding Recorded Investment				$ 57
PCI loans
Troubled debt restructurings
Accruing loans that were classified as TDRs	1,386		1,386		1,437
Non-Accruing loans that were classified as TDRs	69		69		112
Total loans classified as TDRs	1,455		1,455		1,549
Number of TDRs | item		5		5
Pre-Modification Outstanding Recorded Investment		$ 695		$ 695
Post-Modification Outstanding Recorded Investment		$ 695		$ 695
PCI loans | Real Estate Secured | Commercial real estate
Troubled debt restructurings
Accruing loans that were classified as TDRs	910		910		922
Non-Accruing loans that were classified as TDRs	31		31		46
Total loans classified as TDRs	941		941		968
Number of TDRs | item		4		4
Pre-Modification Outstanding Recorded Investment		$ 645		$ 645
Post-Modification Outstanding Recorded Investment		$ 645		$ 645
PCI loans | Real Estate Secured | Land
Troubled debt restructurings
Number of TDRs | item		1		1
Pre-Modification Outstanding Recorded Investment		$ 50		$ 50
Post-Modification Outstanding Recorded Investment		$ 50		$ 50
PCI loans | Real Estate Secured | Construction and land
Troubled debt restructurings
Accruing loans that were classified as TDRs	59		59		54
Total loans classified as TDRs	59		59		54
PCI loans | Commercial | Commercial and industrial
Troubled debt restructurings
Accruing loans that were classified as TDRs	417		417		461
Non-Accruing loans that were classified as TDRs	38		38		66
Total loans classified as TDRs	$ 455		$ 455		$ 527