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Minimum Retirement Age For Eligible Employees Of Postretirement Plans

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Minimum Years Of Service For Eligible Employees Of Postretirement Plans

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Share Based Compensation Arrangement By Share Based Payment Award Vesting Percentage Upon One Year Anniversary Of Date Of Grant

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Shareholder Return Award Performance Measurement Period

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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Percentage of vesting of share-based compensation awards.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the 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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Stock-Based Compensation - Additional Information (Detail) - $ / shares shares in Millions	1 Months Ended		3 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Mar. 31, 2019	Apr. 01, 2018
Share-based Compensation Arrangement by Share-based Payment Award
Estimated annual dividend amount per share			$ 0.36	$ 0.36
Stock price			36.75	$ 47.70
Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award
Weighted average grant date fair value of restricted stock units granted			100,000
Weighted average grant date fair value of restricted stock units granted			$ 10.26
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Period of stock granted to employees and executive officers vest in equal annual installments			4 years
Percentage of common stock price paid			100.00%
Stock options term			7 years
Restricted Stock Units \| Employees
Share-based Compensation Arrangement by Share-based Payment Award
Period of stock granted to employees and executive officers vest in equal annual installments			4 years
Restricted Stock Units \| Director
Share-based Compensation Arrangement by Share-based Payment Award
Period of stock granted to employees and executive officers vest in equal annual installments			1 year
Percentage of awards vesting on the first anniversary of grant date			100.00%
TSR Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Total shareholder return performance measurement period		3 years
Minimum age of retirement to be eligible for PRSUs			60 years
Minimum years of service for retirement to be eligible for PRSUs			10 years
Restricted stock unit awards granted			0.1	0.1
Weighted average grant date fair value of restricted stock units granted			$ 48.47	$ 54.85
Stock price			36.75	47.70
TSR Performance-Based Restricted Stock Units \| Measurement Input, Expected Dividend Payment [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Estimated annual dividend amount per share			$ 0.36	$ 0.36
TSR Performance-Based Restricted Stock Units \| Share-based Compensation Award, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of vesting of target shares upon performance achieved	200.00%
TSR Performance-Based Restricted Stock Units \| Share-based Compensation Award, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of vesting of target shares upon performance achieved	0.00%
PBIT Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Total shareholder return performance measurement period	3 years
Restricted stock unit awards granted			0.1	0.1
Weighted average grant date fair value of restricted stock units granted			$ 35.67	$ 46.62
PBIT Performance-Based Restricted Stock Units \| Share-based Compensation Award, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of vesting of target shares upon performance achieved		200.00%
PBIT Performance-Based Restricted Stock Units \| Share-based Compensation Award, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of vesting of target shares upon performance achieved		0.00%
Service-Based Restricted Stock Units \| Employees
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted			0.6	0.5
Weighted average grant date fair value of restricted stock units granted			$ 46.25	$ 46.58
Service-Based Restricted Stock Units \| Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted			0.1	0.1
Weighted average grant date fair value of restricted stock units granted			$ 35.88	$ 12.17