Dividend Reinvestment Plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Dividend Reinvestment Plan [Line Items]
Dividend reinvestment plan, consideration received on issue	$ 287,000	$ 310,000	$ 1,160,000
Reinvestment Plan [Member]
Dividend Reinvestment Plan [Line Items]
Dividend reinvestment plan, shares issued	21,281	28,778	87,241
Dividend reinvestment plan, consideration received on issue	$ 287,000	$ 310,000	$ 1,200,000