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Pension, Health Care and Postretirement Benefits Other Than Pensions - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) employee pension_plan shares	Dec. 31, 2018 USD ($) employee shares	Dec. 31, 2017 USD ($) employee	Dec. 31, 2016 USD ($)
Defined benefit pension plans
Shares of company stock included in transfer		$ 131.8
Minimum \| Equity Securities
Expected defined benefit payments
Target allocation percentage of plan assets in equity securities		35.00%
Minimum \| Fixed Income Securities
Expected defined benefit payments
Target allocation percentage of plan assets in equity securities		35.00%
Maximum \| Equity Securities
Expected defined benefit payments
Target allocation percentage of plan assets in equity securities		65.00%
Maximum \| Fixed Income Securities
Expected defined benefit payments
Target allocation percentage of plan assets in equity securities		55.00%
Postretirement Health Coverage
Health care plans
Number of active employees entitled to receive benefits under health care plans \| employee		27,030	26,323	26,565
Cost of benefits includes claims incurred and claims incurred but not reported under health care plans		$ 301.6	$ 298.8	$ 281.2
Defined Benefit Pension
Defined benefit pension plans
Fair value of plan assets		325.7	864.1	935.1
Expected defined benefit payments
Expected cash payments, 2020		13.5
Expected cash payments, 2021		13.1
Expected cash payments, 2022		14.0
Expected cash payments, 2023		15.3
Expected cash payments, 2024		16.5
Expected cash payments, 2025-2029		88.9
Amortization of actuarial losses		1.0
Amortization of prior service cost (credit)		1.4
Defined Benefit Pension \| Domestic Defined Benefit Pension Plans
Defined contribution pension plans
Contributions by company		72.7	65.2	38.4
Defined benefit pension plans
Settlement charge		32.4	37.6	(2.0)
Projected benefit obligation		103.0	524.7	916.2	$ 632.8
Fair value of plan assets		125.9	777.0	1,188.6	847.0
Excess (deficient) plan assets over projected benefit obligations		22.9	252.3	272.4
Accumulated benefit obligation		$ 97.2	$ 521.0	913.4
Expected defined benefit payments
Equity investment in domestic defined benefit pension plan assets (in shares) \| shares		0	300,000
Market value of common shares invested in defined benefit pension plan assets			$ 118.0	123.0
Defined Benefit Pension \| Domestic Defined Benefit Pension Plans \| Minimum
Defined contribution pension plans
Contributions by company (percentage)		2.00%
Defined Benefit Pension \| Domestic Defined Benefit Pension Plans \| Maximum
Defined contribution pension plans
Contributions by company (percentage)		7.00%
Defined Benefit Pension \| Foreign Defined Benefit Pension Plans
Defined contribution pension plans
Contributions by company		$ 24.5	19.5	10.5
Defined benefit pension plans
Settlement charge		0.3	(0.4)	0.1
Projected benefit obligation		360.7	315.8	349.6	206.9
Fair value of plan assets		288.1	253.5	280.0	165.0
Excess (deficient) plan assets over projected benefit obligations		$ (72.6)	(62.3)	(69.6)
Number of defined benefit plans \| pension_plan		31
Accumulated benefit obligation		$ 331.7	280.0	308.2
Expected defined benefit payments
Estimated future employer contributions		$ 4.6
Defined Benefit Pension \| Foreign Defined Benefit Pension Plans \| Valspar
Defined benefit pension plans
Number of defined benefit plans \| pension_plan		12
Defined Benefit Pension \| Overfunded Plan \| Domestic Defined Benefit Pension Plans
Defined benefit pension plans
Projected benefit obligation		$ 103.0	524.7	916.2
Fair value of plan assets		125.9	777.0	1,189.0
Excess (deficient) plan assets over projected benefit obligations		22.9	252.3	272.4
Defined Benefit Pension \| Unfunded Plan \| Foreign Defined Benefit Pension Plans
Defined benefit pension plans
Projected benefit obligation		236.6
Fair value of plan assets		143.8
Excess (deficient) plan assets over projected benefit obligations		$ 92.8
Number of foreign defined benefit pension plans unfunded or underfunded \| pension_plan		26
Accumulated benefit obligation		$ 208.3
Postretirement Benefits Other than Pensions
Defined benefit pension plans
Settlement charge				(9.3)
Projected benefit obligation		280.5	$ 274.6	$ 290.8	$ 265.1
Expected defined benefit payments
Expected cash payments, 2020		17.5
Expected cash payments, 2021		16.8
Expected cash payments, 2022		17.2
Expected cash payments, 2023		17.2
Expected cash payments, 2024		18.7
Expected cash payments, 2025-2029		88.3
Amortization of actuarial losses		2.0
Amortization of prior service cost (credit)		$ (1.1)
Number of retired employees entitled to receive postretirement benefits \| employee		3,481	3,498	3,486
Defined benefit plan ultimate health care cost trend rate and prescription drug cost increase rate (percentage)		4.50%
Terminated Plan \| Defined Benefit Pension
Defined benefit pension plans
Settlement charge	$ 32.4
Replacement plan \| Defined Benefit Pension
Defined benefit pension plans
Surplus transferred upon termination and replacement		$ 242.2
Shares of company stock included in transfer		$ 131.8
Shares of company stock included in transfer (in shares) \| shares		300,000