Fair Value Measurements (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) Fund	Dec. 31, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Fair Value Disclosures [Abstract]
Number of mutual funds that invest in debt securities or loans that qualify for credit under the Community Reinvestment Act | Fund	4
Number Of Investments In Mutual Funds That Are Measured At Fair Value Using Net Asset Value Per Share As A Practical Expedient | Fund	2
Redemption notice required to be given to convert capital account, number of days	60 days
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	$ 351,101	$ 377,978
Nonrecurring fair value measurements:
Other real estate owned and repossessed assets	846	846	$ 1,364	$ 1,370
Recurring [Member]
Recurring fair value measurement [Abstract]
Total recurring fair value measurements	351,101	377,978
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Total recurring fair value measurements	54,359	73,594
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Total recurring fair value measurements	295,266	302,936
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Total recurring fair value measurements	0	0
Nonrecurring [Member]
Nonrecurring fair value measurements:
Impaired loans	3,527	4,722
Other real estate owned and repossessed assets	846	846
Total nonrecurring fair value measurements	4,373	5,568
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Nonrecurring fair value measurements:
Impaired loans	0	0
Other real estate owned and repossessed assets	0	0
Total nonrecurring fair value measurements	0	0
Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Nonrecurring fair value measurements:
Impaired loans	0	0
Other real estate owned and repossessed assets	0	0
Total nonrecurring fair value measurements	0	0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Nonrecurring fair value measurements:
Impaired loans	3,527	4,722
Other real estate owned and repossessed assets	846	846
Total nonrecurring fair value measurements	4,373	5,568
U.S. Treasury notes [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	53,592	72,846
U.S. Treasury notes [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	53,592	72,846
U.S. Treasury notes [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	53,592	72,846
U.S. Treasury notes [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
U.S. Treasury notes [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
U.S. Agency notes [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	128,302	139,889
U.S. Agency notes [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	128,302	139,889
U.S. Agency notes [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
U.S. Agency notes [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	128,302	139,889
U.S. Agency notes [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
U.S. Agency mortgage-backed securities [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	33,768	29,378
U.S. Agency mortgage-backed securities [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	33,768	29,378
U.S. Agency mortgage-backed securities [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
U.S. Agency mortgage-backed securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	33,768	29,378
U.S. Agency mortgage-backed securities [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Certificates of Deposit [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	249	249
Certificates of Deposit [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	249	249
Certificates of Deposit [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Certificates of Deposit [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	249	249
Certificates of Deposit [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Non-taxable Municipal securities [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	104,642	105,479
Non-taxable Municipal securities [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	104,642	105,479
Non-taxable Municipal securities [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Non-taxable Municipal securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	104,642	105,479
Non-taxable Municipal securities [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Taxable Municipal securities [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	27,305	26,941
Taxable Municipal securities [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	27,305	26,941
Taxable Municipal securities [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Taxable Municipal securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	27,305	26,941
Taxable Municipal securities [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Mutual funds [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	2,492	2,466
Mutual funds [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	1,016	1,018
Mutual funds [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	16	18
Mutual funds [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	1,000	1,000
Mutual funds [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Mutual funds measured at net asset value [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	1,476	1,448
Trust preferred securities [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	49	50
Trust preferred securities [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	49	50
Trust preferred securities [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	49	50
Trust preferred securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Trust preferred securities [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Equity securities [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	702	680
Equity securities [Member] | Recurring [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	702	680
Equity securities [Member] | Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	702	680
Equity securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	0	0
Equity securities [Member] | Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Recurring fair value measurement [Abstract]
Available-for-sale, at fair value	$ 0	$ 0