Incentive Plans (Summary Of Performance Share Program Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares/units, outstanding	8,117,489	8,660,855	8,060,059	7,275,934
Shares/units, granted	3,682,663	3,148,445	3,641,911
Shares/units, shares issued	(4,025,111)	(3,262,760)	(2,871,367)
Shares/units, forfeited	(499,107)	(429,051)	(169,748)
Weighted average grant date fair value, outstanding	$ 31.20	$ 28.37	$ 22.83	$ 34.98
Weighted average grant date fair value, granted	$ 46.82	$ 40.76	$ 31.57
Weighted average grant date fair value, shares issued	$ 37.18	$ 32.48	$ 16.83
Weighted average grant date fair value, forfeited	$ 43.10	$ 34.58	$ 28.89