Loans and Credit Quality - Nonaccrual Loans by Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	$ 22,899	$ 13,893
Government guarantees on nonaccrual loans	(1,849)	(1,413)
Net nonaccrual loans	21,050	12,480
Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	22,778	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	95	197
Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	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	0	8,750
Government guarantees on nonaccrual loans	0	0
Net nonaccrual loans	0	8,750
30-59 Days Past Due | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	0	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 | Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans		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	6,986	0
Government guarantees on nonaccrual loans	0	0
Net nonaccrual loans	6,986	0
60-89 Days Past Due | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	6,986	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 | Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans		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	3,661	4,375
Government guarantees on nonaccrual loans	(1,413)	(1,413)
Net nonaccrual loans	2,248	2,962
Greater Than 90 Days Past Due | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	3,635	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	0	0
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
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	12,252	768
Government guarantees on nonaccrual loans	(436)	0
Net nonaccrual loans	11,816	768
Current | Commercial
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	12,157	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	95	197
Current | Consumer secured by 1st deeds of trust
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans		$ 0
Current | Consumer other
Nonaccrual Loans By Major Loan Type [Line Items]
Total nonperforming loans	$ 0