Preferred Stock (Details) (USD $)	Dec. 31, 2011
Auction Market Preferred Securities Stock Series [Line Items]
Preferred Stock Shares Authorized	10,000,000
Preferred Stock, Par value	$ 1
Preferred Stock, Outstanding	0
Preferred Stock (Textual) [Abstract]
Preferred stock, Redeemed	2,401,673
Junior Participating Series F [Member]
Auction Market Preferred Securities Stock Series [Line Items]
Preferred Stock Shares Authorized	200,000
Preferred Stock, Par value	$ 1
Preferred Stock, Outstanding	0
Junior Participating Series F - Preferred Stock, Issued	0