Equity and Cash Incentive Program - Outstanding and Exercisable Awards (Details) - Stock Appreciation Rights (SARs) [Member] $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($) $ / shares shares
Exercise Price Range [Line Items]
Number of Outstanding Awards \| shares	5,329,204
Outstanding Awards, Aggregate Intrinsic Value \| $	$ 64,876
Number of Exercisable Awards \| shares	2,661,980
Exercisable Awards, Aggregate Intrinsic Value \| $	$ 36,615
Exercise Price Range 1 [Member]
Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 21.89
Exercise Price Range, Upper Range Limit	$ 37.79
Number of Outstanding Awards \| shares	135,497
Outstanding Awards, Weighted Average Exercise Price	$ 29.61
Outstanding Awards, Weighted Average Remaining Contractual Term	10 months 24 days
Outstanding Awards, Aggregate Intrinsic Value \| $	$ 5,601
Number of Exercisable Awards \| shares	135,497
Exercisable Awards, Weighted Average Exercise Price	$ 29.61
Exercisable Awards, Weighted Average Remaining Contractual Term	10 months 24 days
Exercisable Awards, Aggregate Intrinsic Value \| $	$ 5,601
Exercise Price Range 2 [Member]
Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 40.54
Exercise Price Range, Upper Range Limit	$ 58.69
Number of Outstanding Awards \| shares	2,323,949
Outstanding Awards, Weighted Average Exercise Price	$ 50.13
Outstanding Awards, Weighted Average Remaining Contractual Term	5 years 3 months 18 days
Outstanding Awards, Aggregate Intrinsic Value \| $	$ 48,394
Number of Exercisable Awards \| shares	1,233,688
Exercisable Awards, Weighted Average Exercise Price	$ 31.87
Exercisable Awards, Weighted Average Remaining Contractual Term	3 years 7 months 6 days
Exercisable Awards, Aggregate Intrinsic Value \| $	$ 23,646
Exercise Price Range 3 [Member]
Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 61.79
Exercise Price Range, Upper Range Limit	$ 82.51
Number of Outstanding Awards \| shares	2,869,758
Outstanding Awards, Weighted Average Exercise Price	$ 69.79
Outstanding Awards, Weighted Average Remaining Contractual Term	7 years 3 months 18 days
Outstanding Awards, Aggregate Intrinsic Value \| $	$ 10,881
Number of Exercisable Awards \| shares	1,292,795
Exercisable Awards, Weighted Average Exercise Price	$ 65.33
Exercisable Awards, Weighted Average Remaining Contractual Term	5 years 8 months 12 days
Exercisable Awards, Aggregate Intrinsic Value \| $	$ 7,368

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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