Stock-Based Compensation (Additional Information Regarding Options Outstanding And Exercisable) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares | shares	4,816
Options Exercisable, Number of Shares | shares	2,162
$0.00 - $90.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit	$ 0.00
Exercise price range, upper limit	$ 90.00
Options Outstanding, Number of Shares | shares	406
Options Outstanding, Weighted Average Remaining Contractual Life	1 year
Options Outstanding, Weighted Average Exercise Price	$ 68.96
Options Exercisable, Number of Shares | shares	406
Options Exercisable, Weighted Average Exercise Price	$ 68.96
$90.01 - $110.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit	90.01
Exercise price range, upper limit	$ 110.00
Options Outstanding, Number of Shares | shares	1,609
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 6 months
Options Outstanding, Weighted Average Exercise Price	$ 96.29
Options Exercisable, Number of Shares | shares	983
Options Exercisable, Weighted Average Exercise Price	$ 96.08
$110.01- $145.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit	110.01
Exercise price range, upper limit	$ 145.00
Options Outstanding, Number of Shares | shares	1,871
Options Outstanding, Weighted Average Remaining Contractual Life	4 years 4 months 24 days
Options Outstanding, Weighted Average Exercise Price	$ 119.15
Options Exercisable, Number of Shares | shares	773
Options Exercisable, Weighted Average Exercise Price	$ 121.69
$145.01 - $175.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower limit	145.01
Exercise price range, upper limit	$ 175.00
Options Outstanding, Number of Shares | shares	930
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 2 months 12 days
Options Outstanding, Weighted Average Exercise Price	$ 156.55
Options Exercisable, Weighted Average Exercise Price	$ 0.00