Senior Notes Payable (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Aug. 31, 2012
Senior Notes Payable (Textual) [Abstract]
Senior notes payable	$ 86,250,000	$ 86,250,000	$ 86,250,000
Senior notes issued percentage			7.75%
Senior notes issue price			100.00%
Net proceeds	$ 83,228,000
Maturity period of the assumed debt	Aug. 15, 2022
Notes interest rate	7.75%
Redemption price of notes	100.00%