Stock Based Compensation (Summary Of Option And SOSAR Activity Under Incentive Plan) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock-Based Compensation [Abstract]
Outstanding, beginning of year, Shares	1,694	2,087	1,690
Outstanding, beginning of year, Weighted-Average Exercise Price	$ 490.70	$ 395.46	$ 312.44
Shares granted	460	379	764
Granted, Weighted-Average Exercise Price	$ 457.77	$ 659.12	$ 545.66
Stock option and SOSAR exercises (shares)	(124)	(716)	(315)
Exercised, Weighted-Average Exercise Price	$ 315.87	$ 297.25	$ 310.32
Forfeited, Shares	(113)	(56)	(52)
Forfeited, Weighted-Average Exercise Price	$ 559.25	$ 554.73	$ 419.74
Outstanding, end of year, Shares	1,917	1,694	2,087
Outstanding, end of year, Weighted-Average Exercise Price	$ 490.06	$ 490.70	$ 395.46
Outstanding, Weighted-Average Remaining Years of Contractual Life	4 years 4 months 24 days
Outstanding, Aggregate Intrinsic Value	$ 22,040
Vested and expected to vest, Shares	1,851
Vested and expected to vest, Weighted-Average Exercise Price	$ 489.18
Vested and expected to vest, Weighted-Average Remaining Years of Contractual Life	4 years 3 months 18 days
Vested and expected to vest, Aggregate Intrinsic Value	$ 22,040
Exercisable, Shares	846
Exercisable, Weighted-Average Exercise Price	$ 422.32
Exercisable, Weighted-Average Remaining Years of Contractual Life	3 years 3 months 18 days
Exercisable, Aggregate Intrinsic Value	$ 22,040