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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Outstanding Intrinsic Value

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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested And Expected To Vest Aggregate Intrinsic Value

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Share Based Compensation Arrangement By Share Based Payment Award Shares Reserved For Future Issuance

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Paid

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Treasury Stock, Employer Discretionary Contribution, Shares

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Treasury Stock, Employer Discretionary Contribution, Value

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Aggregate dividends declared during the period for each share of common stock outstanding.

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Face amount or stated value per share of common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of cost to be recognized for option under share-based payment arrangement.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of shares authorized for issuance under share-based payment arrangement.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Gross number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Number of options outstanding, including both vested and non-vested options.

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Per share weighted-average price paid for shares purchased on open market for issuance under share-based payment arrangement.

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Number of shares issued under share-based payment arrangement.

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Price of a single share of a number of saleable stocks of a company.

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Percentage of vesting of award under share-based payment arrangement.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Purchase price of common stock expressed as a percentage of its fair value.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended		12 Months Ended
	Dec. 19, 2020	Sep. 10, 2018	Mar. 31, 2020	Feb. 28, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 14, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preference stock, shares authorized (in shares)					15,000,000.0	15,000,000.0
Preference stock, shares issued (in shares)					0	0
Preferred stock, shares outstanding (in shares)					0	0
Common stock, share authorized (in shares)					150,000,000.0	150,000,000.0
Common stock, par value (in USD per share)					$ 0.10	$ 0.10
Common stock, shares outstanding (in shares)					76,800,000	77,300,000
Common stock, shares issued (in shares)					76,800,000	77,300,000
Number of shares reserved for future issuance (in shares)					21,500,000
Contractual life (years)					7 years
Treasury stock, shares (in shares)					2,100,000	800,000
Stock repurchased (in shares)					1,300,000
Stock repurchased, value					$ 51.7
Discretionary contribution of treasury stock (shares)		2,700,000
Discretionary contribution of treasury stock		$ 95.0
Cash dividends per share (in USD per share)	$ 5.00				$ 5.00	$ 0	$ 0
Share price (in usd per share)					$ 52.85
SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, outstanding (in shares)					900,000	1,200,000
Weighted-average grant date fair value of SARS granted (in USD per share)						$ 37.26	$ 27.53
SARs liabilities paid					$ 7.6	$ 4.3	$ 3.5
Stock-based compensation related to nonvested SARs					$ 0.8
Amortization period (months)					11 months
Expected life (in years)					8 months 12 days	4 years 10 months 24 days	4 years 10 months 24 days
Volatility (percentage)					48.30%	34.79%	35.10%
Risk free interest rate (percentage)					0.11%	1.69%	2.51%
SARs \| Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (years)					7 years
SARs \| Employee \| Vesting Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage (percentage)					33.30%
SARs \| Employee \| Vesting Period Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage (percentage)					33.30%
SARs \| Employee \| Vesting Period Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage (percentage)					33.30%
SARs \| Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (years)					7 years
SARs \| Director \| Vesting Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage (percentage)					50.00%
SARs \| Director \| Vesting Period Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage (percentage)					50.00%
Service Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization period (months)					17 months
Service-based restricted stock outstanding (in shares)					200,000	300,000
Stock-based compensation related to nonvested service-based restricted stock					$ 3.9
Service-based restricted stock outstanding and expected to vest					$ 9.4
Average grant date fair value (in USD per share)						$ 40.70	$ 29.74
Service Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization period (months)					30 months
Service-based restricted stock outstanding (in shares)					100,000	0
Stock-based compensation related to nonvested service-based restricted stock					$ 3.5
Service-based restricted stock outstanding and expected to vest					$ 5.1
Average grant date fair value (in USD per share)					$ 46.00
Restricted stock, granted (in shares)					100,000
Performance-based restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization period (months)					14 months
Service-based restricted stock outstanding (in shares)					500,000	1,000,000.0
Stock-based compensation related to nonvested service-based restricted stock					$ 4.4
Service-based restricted stock outstanding and expected to vest					26.6
Average grant date fair value (in USD per share)						$ 37.27	$ 26.36
Equity instruments other than options vested and expected to vest aggregate intrinsic value					$ 21.5
Restricted stock and restricted stock units, performance based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization period (months)					26 months
Service-based restricted stock outstanding (in shares)					400,000	0
Stock-based compensation related to nonvested service-based restricted stock					$ 6.2
Service-based restricted stock outstanding and expected to vest					$ 19.7
Average grant date fair value (in USD per share)					$ 50.00
Equity instruments other than options vested and expected to vest aggregate intrinsic value					$ 9.8
Restricted stock, granted (in shares)					400,000
Employee stock purchase plan ("ESPP")
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase price (percentage)					85.00%
Shares issued (in shares)					200,000	100,000	100,000
Weighted average price per share (in usd per share)					$ 45.65	$ 45.25	$ 32.11
Employee stock purchase plan ("ESPP") \| 2013 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)					1,500,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, outstanding (in shares)					0	400,000
Exercised in period, intrinsic value					$ 11.0	$ 0.8	$ 0.9
Expected life (in years)						7 years
Volatility (percentage)						33.48%
Risk free interest rate (percentage)						2.62%
Stock, granted (in shares)					0	0
Performance-based common shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)							1 year 3 months
Volatility (percentage)							31.52%
Risk free interest rate (percentage)							2.65%
Performance-based common shares \| Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average grant date fair value (in USD per share)				$ 18.67
Restricted stock, granted (in shares)				100,000
Performance-based common shares \| Executive Officer \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in usd per share)				$ 34.00
Performance-based common shares \| Executive Officer \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in usd per share)				$ 42.00
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amortization period (months)					36 months
Stock-based compensation related to nonvested service-based restricted stock					$ 0.1
Service-based restricted stock outstanding and expected to vest					$ 3.8
Expected life (in years)					8 months 1 day
Volatility (percentage)					35.41%
Risk free interest rate (percentage)					0.72%
Performance Stock Units \| Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average grant date fair value (in USD per share)			$ 37.12
Restricted stock, granted (in shares)			100,000
Performance Stock Units \| Executive Officer \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in usd per share)			$ 57.80
Performance Stock Units \| Executive Officer \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in usd per share)			$ 67.85
2 1/4% Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Debt instrument interest rate stated percentage					2.25%	2.25%		2.25%
2 1/4% Notes \| Convertible senior notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Debt instrument interest rate stated percentage					2.25%