Share-Based Incentive Plans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense	$ 50,000	$ 51,000	$ 48,000
Share based compensation related income tax benefits recognized in earnings	6,000	$ 9,000	$ 16,000
Compensation cost not yet recognized	$ 47,000
Number of shares available for grant (in shares)	6.2
Grants in period, weighted average grant date fair value (USD per share)	$ 27.89	$ 38.34	$ 44.01
Intrinsic value	$ 4,000	$ 30,000	$ 22,000
Weighted average grant date fair value (USD per share)	$ 127.26	$ 157.09	$ 164.26
Total fair value, options vested in period	$ 28,000	$ 29,000	$ 29,000
Nonemployee director equity award	$ 145
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Terms of award	10 years
Tax benefit from stock options exercised	$ 1,000	7,000	8,000
Proceeds from stock options exercised	$ 8,000	$ 17,000	$ 34,000
Restricted Stock Units (RSUs) | Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Restricted Stock Units (RSUs) | Executives | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Restricted Stock Units (RSUs) | Executives | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	7 years
Performance Stock Units | Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Performance Stock Units | Management | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measures	0.00%
Performance Stock Units | Management | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measures	200.00%