Shareholders' Equity (Details) (DRIP [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
DRIP [Member]
Shares issued under dividend reinvestment plan
Amounts Received	$ 34,650,730	$ 37,054,626	$ 19,448,937
Less: Dividends Reinvested	1,858,491,000	1,861,987	1,390,899
Amounts Received, net	$ 32,792,239	$ 35,192,639	$ 18,058,038
Number of Shares Issued	3,554,191	3,658,010	1,780,043