Common and Preferred Stock, Employee Stock Purchase Plan (Details) (USD $)	1 Months Ended	12 Months Ended
	Aug. 31, 2011	Dec. 31, 2011
Employee Stock Purchase Plan [Abstract]
Employee eligibility threshold		5.00%
Employee payroll deductions, minimum		$ 10
Employee payroll deductions maximum		$ 350
Repurchase of common stock	400,000
Employee Stock [Member]
Employee Stock Purchase Plan [Abstract]
Maximum number of shares of common stock which may be purchased under the ESPP (in shares)		734,000
Additional shares of common stock to be reserved for issuance under the DRIP Feature of the ESPP (in shares)		50,000
Number of shares of common stock available for purchase under the ESPP (in shares)		432,756