Summary Of Significant Accounting Policies Summary of Significant Accounting Policies (Summary of Nonvested Shares Related To Long-Term Incentive Plan) (Details) (Performance Shares, USD $)	3 Months Ended
	Mar. 31, 2014
Performance Shares
Share Units
Share Units, Nonvested as of January 1, 2014	1,218,544
Share Units, Granted	680,606	[1]
Share Units, Forfeitures	(46,758)
Share Units, Vested	(116,297)	[2]
Share Units, Nonvested as of March 31, 2014	1,736,095
Weighted-average Fair Value per Unit at Grant Date
Weighted-average Fair Value per Unit, Nonvested as of January 1, 2014	$ 33.23
Weighted-average Fair Value per Unit, Grants	$ 38.90	[1]
Weighted-average Fair Value per Unit, Forfeitures	$ 33.29
Weighted-average Fair Value per Unit, Vested	$ 38.81	[2]
Weighted-average Fair Value per Unit, Nonvested as of March 31, 2014	$ 35.08
Performance period	3 years

[1] Includes performance share units (share units) granted to certain executive and nonexecutive officers and other eligible employees in 2014 under the 2006 Plan.

[2] Share units vested due to the attainment of retirement eligibility by certain employees. Actual shares issued for retirement-eligible employees will vary depending on actual performance over the three-year measurement period.