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Defined Benefit Plan, Benefit Obligation, NonCash Settlement

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Number of Multiemployer Plans

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Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.

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Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

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Amount of payment to participant of defined benefit plan which decreases benefit obligation. 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.

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

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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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Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year.

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Percentage of plan assets to benefit obligation of defined benefit plan.

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Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets.

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Amount of plan asset for defined benefit plan with accumulated benefit obligation in excess of plan assets.

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Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets.

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Amount of payment, which decreases plan assets of defined benefit plan, for irrevocable action relieving primary responsibility for benefit obligation and eliminating risk for obligation and assets used to effect settlement. Transaction constituting settlement includes, but is not limited to, making lump-sum cash payment to participant in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contract.

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Amount of cost for defined contribution plan.

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Amount of increase (decrease) in cost for defined contribution plan.

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- Definition

Percentage of contributions required of employer under collective bargaining arrangement to total contributions required under all collective bargaining arrangements for pension and other postretirement plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

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Amount of contributions made to multiemployer plan by all employers who participate in plan.

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Amount of the obligation recognized by withdrawing from a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

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Amount, after tax, of cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Amount, after tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount of cash outflow for pension benefit. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree. Excludes other postretirement benefit.

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Pensions and Other Postretirement Benefits - Additional Disclosures (Details) $ in Millions		3 Months Ended			12 Months Ended
	Jan. 28, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($) plan	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Lump sum settlements			$ 150.2
Net actuarial loss			(39.2)
Aggregate ABO			1,043.0		$ 1,043.0
Aggregate PBO			1,048.6		1,048.6
Aggregate fair value of plan assets			942.9		942.9
Multiemployer Plan
Multiemployer plans, plan contributions					0.6	$ 3.4
Multiemployer withdrawal liability			$ 30.8		$ 30.8	32.4
Number of multiemployer plans \| plan					1
Percent of total plan contributions for the most recent plan year					5.00%
Defined Contribution Plans
Contributions to defined contribution plans					$ 57.6	54.6	$ 37.7
Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Transfer of remaining pension benefit obligation to annuity	$ 750.0
Net actuarial loss	$ 150.0
Red Zone
Multiemployer Plan
Plan funded percentage			65.00%		65.00%
Yellow Zone
Multiemployer Plan
Plan funded percentage			80.00%		80.00%
Green Zone
Multiemployer Plan
Plan funded percentage			80.00%		80.00%
PIUMPF
Multiemployer Plan
Multiemployer withdrawal liability			$ 4.4		$ 4.4
Graphic Communications Conference of International Brotherhood of Teamster Pension Fund
Multiemployer Plan
Multiemployer withdrawal liability			$ 4.4		4.4
Pension Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Transfer of remaining pension benefit obligation to annuity					$ 150.2	$ 0.0
Weighted average discount rate			2.69%		2.69%	4.14%
Accumulated Benefit Obligation			$ 1,249.8		$ 1,249.8	$ 1,240.2
Company's contributions to its pension plans					11.3	5.8
Benefit payments made					67.2	65.4
Pension Benefit Plans \| Forecast
Defined Benefit Plan Disclosure [Line Items]
Noncash settlement charge		$ 150.0
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Transfer of remaining pension benefit obligation to annuity					$ 0.0	$ 0.0
Weighted average discount rate			3.22%		3.22%	4.29%
Company's contributions to its pension plans					$ 1.2	$ 1.9
Benefit payments made					1.2	$ 1.9
Expected contributions in 2019			$ 3.0		$ 3.0
Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation horizon term					3 years
Minimum \| Corporate Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Debt securities maturity term			1 year		1 year
Minimum \| Pension Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Expected contributions in 2019			$ 10.0		$ 10.0
Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation horizon term					5 years
Maximum \| Corporate Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Debt securities maturity term			30 years		30 years
Maximum \| Pension Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Expected contributions in 2019			$ 20.0		$ 20.0
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit plan				$ 75.0
UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit plan				$ 6.8
NACP Combination
Defined Contribution Plans
Increase in contributions due to NACP Combination					$ 16.9