Fair Value Measurements - Financial Assets Measured on a Recurring Basis (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	$ 346,502,000	$ 340,349,000
Federal agencies and GSEs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	104,054,000	81,452,000
Mortgage-backed and CMOs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	79,493,000	70,930,000
State and municipal
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	147,515,000	175,891,000
Corporate
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	13,492,000	10,590,000
Equity securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	1,948,000	1,486,000
Recurring
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	346,502,000	340,349,000
Recurring | Federal agencies and GSEs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	104,054,000	81,452,000
Recurring | Mortgage-backed and CMOs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	79,493,000	70,930,000
Recurring | State and municipal
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	147,515,000	175,891,000
Recurring | Corporate
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	13,492,000	10,590,000
Recurring | Equity securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	1,948,000	1,486,000
Level 1
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 1 | Recurring
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 1 | Recurring | Federal agencies and GSEs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 1 | Recurring | Mortgage-backed and CMOs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 1 | Recurring | State and municipal
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 1 | Recurring | Corporate
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 1 | Recurring | Equity securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 2
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	346,502,000	338,863,000
Level 2 | Recurring
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	346,502,000	338,863,000
Level 2 | Recurring | Federal agencies and GSEs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	104,054,000	81,452,000
Level 2 | Recurring | Mortgage-backed and CMOs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	79,493,000	70,930,000
Level 2 | Recurring | State and municipal
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	147,515,000	175,891,000
Level 2 | Recurring | Corporate
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	13,492,000	10,590,000
Level 2 | Recurring | Equity securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	1,948,000	0
Level 3
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	1,486,000
Level 3 | Recurring
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	1,486,000
Level 3 | Recurring | Federal agencies and GSEs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 3 | Recurring | Mortgage-backed and CMOs
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 3 | Recurring | State and municipal
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 3 | Recurring | Corporate
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	0	0
Level 3 | Recurring | Equity securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value	$ 0	$ 1,486,000