Loans and Credit Quality - Nonaccrual Loans by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	$ 13,513	$ 13,893
Government guarantees on nonaccrual loans	(1,478)	(1,413)
Net nonaccrual loans	12,035	12,480
Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	13,205	13,500
Real estate term owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	29
Real estate term non-owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	109	197
Real estate term other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	6	0
Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	167	167
Consumer other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	26	0
30-59 Days Past Due
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	28	8,750
Government guarantees on nonaccrual loans	0	0
Net nonaccrual loans	28	8,750
30-59 Days Past Due | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	28	8,750
30-59 Days Past Due | Real estate term owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans		0
30-59 Days Past Due | Real estate term non-owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	0
30-59 Days Past Due | Real estate term other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0
30-59 Days Past Due | Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	0
30-59 Days Past Due | Consumer other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0
60-89 Days Past Due
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	427	0
Government guarantees on nonaccrual loans	(65)	0
Net nonaccrual loans	362	0
60-89 Days Past Due | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	427	0
60-89 Days Past Due | Real estate term owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans		0
60-89 Days Past Due | Real estate term non-owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	0
60-89 Days Past Due | Real estate term other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0
60-89 Days Past Due | Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	0
60-89 Days Past Due | Consumer other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0
Greater Than 90 Days Past Due
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	5,665	4,375
Government guarantees on nonaccrual loans	(1,413)	(1,413)
Net nonaccrual loans	4,252	2,962
Greater Than 90 Days Past Due | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	5,357	4,208
Greater Than 90 Days Past Due | Real estate term owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans		0
Greater Than 90 Days Past Due | Real estate term non-owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	109	0
Greater Than 90 Days Past Due | Real estate term other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	6
Greater Than 90 Days Past Due | Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	167	167
Greater Than 90 Days Past Due | Consumer other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	26
Current
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	7,393	768
Government guarantees on nonaccrual loans	0	0
Net nonaccrual loans	7,393	768
Current | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	7,393	542
Current | Real estate term owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans		29
Current | Real estate term non-owner occupied
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	197
Current | Real estate term other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0
Current | Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	$ 0
Current | Consumer other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	$ 0