Investment Securities (Held-to-maturity Securities) (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	$ 49,758,000	$ 45,275,000
Gross unrealized gains	199,000	1,890,000
Gross unrealized losses	(1,328,000)	(41,000)
Held-to-maturity securities, total fair value	48,629,000	47,124,000
Gross realized gains or losses	0	0
States and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	3,853,000	3,860,000
Gross unrealized gains	135,000	390,000
Gross unrealized losses	(15,000)	0
Held-to-maturity securities, total fair value	3,973,000	4,250,000
Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	38,046,000	33,494,000
Gross unrealized gains	54,000	1,107,000
Gross unrealized losses	(1,202,000)	(41,000)
Held-to-maturity securities, total fair value	36,898,000	34,560,000
Commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	7,859,000	7,921,000
Gross unrealized gains	10,000	393,000
Gross unrealized losses	(111,000)	0
Held-to-maturity securities, total fair value	$ 7,758,000	$ 8,314,000