Stock Compensation Plans (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended					12 Months Ended		12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	May 06, 2005	Dec. 31, 2011 Change in plan assets [Member]	May 06, 2005 Prior Plan [Member]	Dec. 31, 2011 SOSARs and Stock Options [Member] years	Dec. 31, 2011 Restricted Stock Awards [Member] years	Dec. 31, 2011 Performance Share Units [Member] years	Dec. 31, 2010 Performance Share Units [Member]	Dec. 31, 2009 Performance Share Units [Member]	Dec. 31, 2011 Employee Stock [Member]	Dec. 31, 2008 Stock Only Stock Appreciation Rights [Member]	Dec. 31, 2007 Stock Only Stock Appreciation Rights [Member]	Dec. 31, 2006 Stock Only Stock Appreciation Rights [Member]	Dec. 31, 2011 Executive Officer [Member] Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares remained available	396,000						426,000						266,000
SOSARs granted, Shares									47,000	77,000
Maximum term for options granted						10 years
Period for recognition of compensation cost								0.17	2.0	2.0
Total unrecognized compensation cost								$ 0.1	$ 1.3	$ 2.9
Number of shares issued									46,862								77,025
Term of granting options to directors and management personnel														5 years	5 years	5 years
General vesting period of options granted									3 years					3 years	after three years	after three years
Percentage of maximum amount available for issuance										40.00%	100.00%	100.00%
Term of Treasury issues													1 year
Stock Compensation Plans (Textual) [Abstract]
Number of shares authorized to grant under LT Plan					400,000
Number of additional shares available under LT Plan				500,000
Compensation expense recognized	$ 4.1	$ 2.6	$ 2.7