Shareholder Rights Plan (Narrative) (Details) (USD $)	120 Months Ended
	May 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Shareholder Rights Plan
Common stock, par value	$ 0.01	$ 0.01	$ 0.01
Date from which warrant or rights are exercisable	May 31, 2002
Expiration date of warrants or rights outstanding	May 31, 2012