Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014 Property Fund		Dec. 31, 2013 Property
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of mutual funds that invest in debt securities or loans that qualify for credit under the Community Reinvestment Act	2
Redemption notice required to be given to convert capital account, number of days	60 days
Nonrecurring fair value measurements:
Number of impaired other real estate owned properties	1		7
Other real estate owned impaired carrying value	$ 99		$ 404
Fair value of other real estate owned properties	94		328
Impaired charges related to other real estate owned properties included in non-interest expense for the period	5		76
Number of other real estate owned properties sold	2		12
Other real estate owned properties sold during period carrying value	150
Proceeds from sale of other real estate owned properties	136
Gains (losses) on sales of other real estate properties	(14)		256
Realized gain (loss) from sale of repossessed assets			(2)
Recurring [Member]
Investment securities available-for-sale [Abstract]
U.S. Treasury notes	35,172		12,894
U.S. Agency notes	122,461		106,675
U.S. Agency mortgage-backed securities	43,829		40,309
Certificates of deposit with other banks	3,095		1,501
Municipal securities:
Non-taxable	84,486		75,333
Taxable	16,831		17,309
Mutual funds	2,395		2,380
Trust preferred securities	50		147
Equity securities	1,744		1,693
Total recurring fair value measurements	310,063		258,241
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Investment securities available-for-sale [Abstract]
U.S. Treasury notes	35,172		12,894
U.S. Agency notes	0		0
U.S. Agency mortgage-backed securities	0		0
Certificates of deposit with other banks	0		0
Municipal securities:
Non-taxable	0		0
Taxable	0		0
Mutual funds	1,395		1,380
Trust preferred securities	50		147
Equity securities	1,744		1,693
Total recurring fair value measurements	38,361		16,114
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale [Abstract]
U.S. Treasury notes	0		0
U.S. Agency notes	122,461		106,675
U.S. Agency mortgage-backed securities	43,829		40,309
Certificates of deposit with other banks	3,095		1,501
Municipal securities:
Non-taxable	84,486		75,333
Taxable	16,831		17,309
Mutual funds	1,000		1,000
Trust preferred securities	0		0
Equity securities	0		0
Total recurring fair value measurements	271,702		242,127
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale [Abstract]
U.S. Treasury notes	0		0
U.S. Agency notes	0		0
U.S. Agency mortgage-backed securities	0		0
Certificates of deposit with other banks	0		0
Municipal securities:
Non-taxable	0		0
Taxable	0		0
Mutual funds	0		0
Trust preferred securities	0		0
Equity securities	0		0
Total recurring fair value measurements	0		0
Nonrecurring [Member]
Nonrecurring fair value measurements:
Impaired loans	4,345		8,530
Other real estate owned and repossessed assets	1,799	[1]	1,463	[2]
Total nonrecurring fair value measurements	6,144		9,993
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	[1]	0	[2]
Total nonrecurring fair value measurements	0		0
Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Nonrecurring fair value measurements:
Impaired loans	349		773
Other real estate owned and repossessed assets	1,799	[1]	1,463	[2]
Total nonrecurring fair value measurements	2,148		2,236
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Nonrecurring fair value measurements:
Impaired loans	3,996		7,757
Other real estate owned and repossessed assets	0	[1]	0	[2]
Total nonrecurring fair value measurements	3,996		7,757
Nonrecurring [Member] | Total Gains (Losses) [Member]
Nonrecurring fair value measurements:
Impaired loans	0		0
Other real estate owned and repossessed assets	(19)	[1]	178	[2]
Total nonrecurring fair value measurements	$ (19)		$ 178

[1] One other real estate owned property with a total carrying amount of $99,000 was written down to its fair value of $94,000, resulting in an impairment charge of $5,000. Two other real estate owned properties with a total carrying amount of $150,000 were sold for a combined total of $136,000, resulting in a net loss of $14,000. The write-downs and losses,were included in other non-interest expense for the period.

[2] Seven other real estate owned properties with a total carrying amount of $404,000 were written down to their combined fair value of $328,000, resulting in an impairment charge of $76,000. Twelve properties were sold for a combined net gain of $256,000. The write-downs and net gain were included in other real estate owned expense for the period. A repossessed asset was sold for a loss of $2,000, which was included in other non-interest expense for the period.