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Award payout percentage of target at 50 percent

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Award payout percentage at the 25th percentile level of achievement

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Award payout percentage at the 50th percentile level of achievement

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Award payout percentage at the 75th percentile level of achievement

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Base-year adjusted net revenue amount

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Expected Defined Benefit Plans Contribution Within One Year

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Number of stock plans

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Pension Plans, Postretirement and Other Employee Benefits [Line Items]

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Percentage level of achievement - 13 percent average growth

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Percentage level of achievement - 19 percent average growth

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Percentage level of achievement - 25 percent average growth

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Percentage level of achievement - less than 13 percent average growth

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Percentage of equity investments in mutual fund

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Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

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Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

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Amount of cost for defined contribution plan.

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Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

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Percentage employer matches of the employee's percentage contribution matched.

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Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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Amount of paid and unpaid cash, stock, and paid-in-kind dividends declared for award under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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

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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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Employee Benefit Plans (Narrative) (Detail) - USD ($)	12 Months Ended
Employee Benefit Plans (Narrative) (Detail) - USD ($)	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Percentage of equity investments in mutual fund	67.00%
Net periodic benefit cost, Expected return on plan assets	7.25%	7.25%	7.25%
Expected defined benefit plans contribution within a year	$ 1,200,000
Defined contribution plan, cost	$ 28,000,000	$ 23,800,000
Number of stock plans	3
Dividends, share-based compensation	$ 0.87	$ 0.75	$ 0.72
Weighted-average risk-free interest rate	4.45%	0.77%	0.19%
Options awarded during period	0	0	0
Performance Shares [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant	505,456
Base-year adjusted net revenue amount	$ 713,800,000	$ 415,900,000
Base-year calculation basis point adjustment	0.30%	0.30%
Percentage level of achievement - 13 percent average growth	13.00%	13.00%
Award payout percentage of target at 50 percent	50.00%	50.00%
Percentage level of achievement - 19 percent average growth	19.00%	19.00%
Award payout percentage of target at 100 percent	100.00%	100.00%
Percentage level of achievement - 25 percent average growth	25.00%	25.00%
Award payout percentage of target at 150 percent	150.00%	150.00%
Award payout percentage at less than 25th percentile level of achievement	0.00%
Award payout percentage at the 25th percentile level of achievement	50.00%
Award payout percentage at the 50th percentile level of achievement	100.00%
Award payout percentage at the 75th percentile level of achievement	150.00%
Performance Shares [Member] \| Pro Forma [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Granted in period, number of shares/units	35,015	30,723	48,409
Equity Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target asset allocation percentage	64.00%
Fixed Income Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target asset allocation percentage	31.00%
Two Thousand Fifteen Plan [Member] \| Stock Options [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Vesting period of options awarded, years	4 years
Two Thousand Fifteen Plan [Member] \| Non Vested Stock Awards and Stock Units [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Two Thousand Fifteen Plan [Member] \| Non Vested Stock Awards and Stock Units [Member] \| 2021
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Vesting period of options awarded, years	3 years
Two Thousand Fifteen Plan [Member] \| Non Vested Stock Awards and Stock Units [Member] \| Prior to 2021
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Vesting period of options awarded, years	4 years
Minimum [Member] \| Performance Shares [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Percentage level of achievement - less than 13 percent average growth	13.00%	13.00%
Award payout percentage of target at 0 percent	0.00%	0.00%
Maximum [Member] \| Performance Shares [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Granted in period, number of shares/units	52,527	46,086	72,618
Other Pension Plan [Member] \| Qualified Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Participants contribution eligible for match	100.00%
Defined contribution plan, cost			$ 17,900,000
Other Pension Plan [Member] \| Qualified Plan [Member] \| Minimum [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Maximum annual contributions per employee, percent	2.00%
Other Pension Plan [Member] \| Qualified Plan [Member] \| Maximum [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Maximum annual contributions per employee, percent	50.00%
Employer matching contribution, percent of employees' gross pay	6.00%