Stock-Based Compensation (Details 3) (Restricted stock, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted stock
Number
Unvested at the beginning of the period (in shares)	113,910	95,007	81,682
Shares awarded (in shares)	55,275	57,156	41,991
Restrictions lapsed and shares released to employees/directors (in shares)	(39,909)	(30,782)	(21,333)
Shares forfeited (in shares)	(4,720)	(7,471)	(7,333)
Unvested at the end of the period (in shares)	124,556	113,910	95,007
Grant date weighted-average cost
Unvested at the beginning of the period (in dollars per share)	$ 22.55	$ 22.49	$ 21.58
Fair value of awards granted (in dollars per share)	$ 22.93	$ 22.71	$ 23.96
Restrictions lapsed and shares released to employees/directors (in dollars per share)	$ 22.29	$ 22.66	$ 21.82
Shares forfeited (in dollars per share)	$ 23.45	$ 22.59	$ 22.61
Unvested at the end of the period (in dollars per share)	$ 22.77	$ 22.55	$ 22.49