Compensation Programs (Schedule Of Service-Based Stock Awards) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares vesting in period	(90,097)
Service-Based Stock Awards [Member] | 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Year of Grant	2007
Grant Date Fair Value Per Share	$ 12.93
Total Original Grants	156,000
Vested			70,009
Forfeited			12,499
Service-Based Stock Awards [Member] | 2007 [Member] | Remaining Shares Vesting In: 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares vesting in period	22,498	[1]
Service-Based Stock Awards [Member] | 2007 [Member] | Remaining Shares Vesting In: 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares vesting in period	22,497
Service-Based Stock Awards [Member] | 2007 [Member] | Remaining Shares Vesting In: 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares vesting in period	22,497
Service-Based Stock Awards [Member] | 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Year of Grant	2008
Grant Date Fair Value Per Share	$ 12.87
Total Original Grants	6,000
Vested			6,000
Service-Based Stock Awards [Member] | 2009 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Year of Grant	2009
Grant Date Fair Value Per Share	$ 11.39
Total Original Grants	6,000
Vested			6,000
Service-Based Stock Awards [Member] | 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Year of Grant	2010
Grant Date Fair Value Per Share	$ 11.64
Total Original Grants	12,000
Vested			12,000
Service-Based Stock Awards [Member] | 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Year of Grant	2011
Grant Date Fair Value Per Share	$ 13.23
Total Original Grants	24,000
Service-Based Stock Awards [Member] | 2011 [Member] | Remaining Shares Vesting In: 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares vesting in period	24,000

[1] Shares vested in January 2012.