Pensions and Postretirement Benefits - Schedule of Change in Plan Assets and Underfunded Status at End of Year (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan, Change in Fair Value of Plan Assets
Fair value of plan assets at beginning of year	$ 351.4	$ 353.4
Fair value of plan assets at end of year	353.4
Pension Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets
Fair value of plan assets at beginning of year	351.4	353.4
Actual return on plan assets	12.2	53.5
Administrative expenses	0.0	(0.7)
Benefits paid	(14.4)	(13.0)
Company contributions	0.3	4.4
Plan combination (acquisitions/divestitures)	0.0	(4.1)
Other	(0.1)	(0.2)
Fair value of plan assets at end of year	$ 353.4	$ 313.5

Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses.

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- Definition

Amount of administration expense of defined benefit plan which decreases plan assets. Excludes plan administration expense paid by employer.

+ References

No definition available.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

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- Definition

Amount of decrease in plan assets of defined benefit plan from disposal or classification as held-for-sale.

+ References

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- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

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- Definition

Amount of defined benefit plan cost (credit), classified as other.

+ References

No definition available.

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- Definition

Amount of payment to participant under defined benefit plan which decreases plan assets. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.

+ References

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