Compensation Programs (Schedule Of Performance-Based Stock Awards) (Details) (USD $)	3 Months Ended						12 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Performance-Based Stock Awards [Member]	Mar. 31, 2012 2008 [Member]	Mar. 31, 2012 2008 [Member] Performance-Based Stock Awards [Member]		Dec. 31, 2011 2008 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 2009 [Member]	Mar. 31, 2012 2009 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 2010 [Member]	Mar. 31, 2012 2010 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 2011 [Member]	Mar. 31, 2012 2011 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 Remaining Shares With Initial Measurement Periods 2012 [Member] 2008 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 Remaining Shares With Initial Measurement Periods 2012 [Member] 2009 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 Remaining Shares With Initial Measurement Periods 2013 [Member] 2009 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 Remaining Shares With Initial Measurement Periods 2013 [Member] 2010 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 Remaining Shares With Initial Measurement Periods 2014 [Member] 2010 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 Remaining Shares With Initial Measurement Periods 2014 [Member] 2011 [Member] Performance-Based Stock Awards [Member]	Mar. 31, 2012 Remaining Shares With Initial Measurement Periods 2015 [Member] 2011 [Member] Performance-Based Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Year of Grant					2008				2009		2010		2011
Grant Date Fair Value Per Share					$ 10.18				$ 14.33		$ 12.44		$ 12.72
Total Original Grants	0	0		225,000	140,658	[1]		225,000	110,917	60,000	128,766	72,000	132,490
Expiration date of grant	July 1, 2014				2015				2016		2017		2018
Remaining Shares Vesting in Period	(90,097)													67,595	55,043	55,035	64,087	64,077	66,247	66,243
Performance-based awards vested, shares			67,599
Percentage of performance based awards granted, actual							50.00%

[1] The performance criteria for the first three-year measurement period ending December 31, 2011 was met resulting in the vesting of 67,599 shares associated with the first 50% of this grant.