Preferred Share Purchase Rights (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Preferred Share Purchase Rights (Additional Textual) [Abstract]
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred Share Purchase Rights (Textual) [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Series A Junior Participating Preferred Stock [Member]
Preferred Share Purchase Rights (Additional Textual) [Abstract]
Preferred stock, shares authorized	250,000