Preferred Stock (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Class of Stock [Line Items]
Preferred stock shares, Par value	$ 100.00	$ 100.00
Preferred stock shares outstanding	390,000
Cumulative No Par Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock shares authorized	1,600,000
Cumulative Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock shares authorized	390,000
Optional redemption percentage of par value, minimum (in hundredths)	101.00%
Optional redemption percentage of par value, maximum (in hundredths)	103.70%
Preference Stock [Member]
Class of Stock [Line Items]
Preferred stock shares authorized	11,000,000