Equity Incentive Plan (Details) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding, Unvested restricted stock at beginning of the period	249,082	250,180	216,920
Shares Outstanding, Restricted stock granted	83,210	87,950	94,850
Shares Outstanding Restricted stock vested	(79,588)	(73,368)	(55,870)
Shares Outstanding, Restricted stock forfeited	(14,078)	(15,680)	(5,720)
Shares Outstanding, Unvested restricted stock at end of the period	238,626	249,082	250,180
Weighted Average Grant Date Fair Value, Unvested restricted stock at beginning of the period (in dollars per share)	$ 24.33	$ 22.66	$ 21.74
Weighted Average Grant Date Fair Value, Restricted stock granted (in dollars per share)	$ 28.72	$ 27.70	$ 24.40
Weighted Average Grant Date Fair Value, Restricted stock vested (in dollars per share)	$ 22.64	$ 22.50	$ 21.87
Weighted Average Grant Date Fair Value, Restricted stock forfeited (in dollars per share)	$ 26.03	$ 25.01	$ 24.32
Weighted Average Grant Date Fair Value, Unvested restricted stock at end of the period (in dollars per share)	$ 26.24	$ 24.33	$ 22.66