Share-Based Awards (Stock Options Outstanding By Price Range) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Contractual Life, options outstanding (in years)	4 years
Options | shares	1,404
Weighted-Average Exercise Price, options outstanding (in dollars per share)	$ 48
Weighted-Average Contractual Life, Options exercisable (in years)	3 years 8 months
Options exercisable | shares	1,309
Weighted-Average Exercise Price, Options exercisable (in dollars per share)	$ 47
$10.01 to $20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Contractual Life, options outstanding (in years)	1 year 2 months
Options | shares	151
Weighted-Average Exercise Price, options outstanding (in dollars per share)	$ 13
Lower Range Limit (in dollars per share)	10.01
Upper Range Limit (in dollars per share)	$ 20
$20.01 to $30
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Contractual Life, options outstanding (in years)	2 years 1 month
Options | shares	145
Weighted-Average Exercise Price, options outstanding (in dollars per share)	$ 24
Lower Range Limit (in dollars per share)	20.01
Upper Range Limit (in dollars per share)	$ 30
$30.01 to $40
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Contractual Life, options outstanding (in years)	1 month
Options | shares	37
Weighted-Average Exercise Price, options outstanding (in dollars per share)	$ 39
Lower Range Limit (in dollars per share)	30.01
Upper Range Limit (in dollars per share)	$ 40
$40.01 to $50
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Contractual Life, options outstanding (in years)	3 years 7 months
Options | shares	239
Weighted-Average Exercise Price, options outstanding (in dollars per share)	$ 44
Lower Range Limit (in dollars per share)	40.01
Upper Range Limit (in dollars per share)	$ 50
$50.01 to $60
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Contractual Life, options outstanding (in years)	4 years 7 months
Options | shares	193
Weighted-Average Exercise Price, options outstanding (in dollars per share)	$ 52
Lower Range Limit (in dollars per share)	50.01
Upper Range Limit (in dollars per share)	$ 60
$60.01 to $70
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Contractual Life, options outstanding (in years)	5 years 2 months
Options | shares	639
Weighted-Average Exercise Price, options outstanding (in dollars per share)	$ 63
Lower Range Limit (in dollars per share)	60.01
Upper Range Limit (in dollars per share)	$ 70