Capital Stock And Share-Based Compensation (Schedule Of Non-Vested Stock Award Activity) (Details) (Non-Vested Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2011
Non-Vested Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Non-vested Beginning Balance	408,350
Weighted average grant date fair Value, Non-vested Beginning Balance	$ 45.43
Shares, Granted	458,869
Weighted average grant date fair Value, Granted	$ 27.05
Shares, Vested	(160,973)
Weighted average grant date fair Value, Vested	$ 42.94
Shares, Canceled, forfeited or expired	(137,396)
Weighted average grant date fair Value, Canceled, forfeited or expired	$ 39.91
Shares, Non-vested Ending Balance	568,850
Weighted average grant date fair Value, Non-vested Ending Balance	$ 32.64