Represents the per unit value of the investment.

No definition available.

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- Definition

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.

+ References

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- Definition

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.

+ References

No definition available.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Employee Benefit Plans - Defined Benefit Pension Plans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / item	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Employee benefit plans
Fair value of plan assets	$ 441.7	$ 397.2
Fixed income common trust funds
Employee benefit plans
Fair value of plan assets	255.6	228.5
Commingled global fund allocations
Employee benefit plans
Fair value of plan assets	110.3	83.3
Global equity common trust funds
Employee benefit plans
Fair value of plan assets	30.1	41.1
U.S. Government securities
Employee benefit plans
Fair value of plan assets	24.5	24.0
Short-term investments
Employee benefit plans
Fair value of plan assets	$ 7.1	7.8
Value of short-term investments (in dollars per unit) \| $ / item	1.00
Non-U.S. Government securities
Employee benefit plans
Fair value of plan assets	$ 13.2	11.5
Other
Employee benefit plans
Fair value of plan assets	0.9	1.0
Quoted Prices in Active Markets for Identical Assets (Level 1)
Employee benefit plans
Fair value of plan assets	7.1	7.8
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fixed income common trust funds
Employee benefit plans
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Commingled global fund allocations
Employee benefit plans
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Global equity common trust funds
Employee benefit plans
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| U.S. Government securities
Employee benefit plans
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term investments
Employee benefit plans
Fair value of plan assets	7.1	7.8
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Non-U.S. Government securities
Employee benefit plans
Fair value of plan assets	0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Other
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Observable Inputs (Level 2)
Employee benefit plans
Fair value of plan assets	433.7	388.4
Significant Observable Inputs (Level 2) \| Fixed income common trust funds
Employee benefit plans
Fair value of plan assets	255.6	228.5
Significant Observable Inputs (Level 2) \| Commingled global fund allocations
Employee benefit plans
Fair value of plan assets	110.3	83.3
Significant Observable Inputs (Level 2) \| Global equity common trust funds
Employee benefit plans
Fair value of plan assets	30.1	41.1
Significant Observable Inputs (Level 2) \| U.S. Government securities
Employee benefit plans
Fair value of plan assets	24.5	24.0
Significant Observable Inputs (Level 2) \| Short-term investments
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Observable Inputs (Level 2) \| Non-U.S. Government securities
Employee benefit plans
Fair value of plan assets	13.2	11.5
Significant Observable Inputs (Level 2) \| Other
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3)
Employee benefit plans
Fair value of plan assets	0.9	1.0
Significant Unobservable Inputs (Level 3) \| Fixed income common trust funds
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3) \| Commingled global fund allocations
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3) \| Global equity common trust funds
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3) \| U.S. Government securities
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3) \| Short-term investments
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3) \| Non-U.S. Government securities
Employee benefit plans
Fair value of plan assets	0.0	0.0
Significant Unobservable Inputs (Level 3) \| Other
Employee benefit plans
Fair value of plan assets	$ 0.9	$ 1.0
United States
Employee benefit plans
Actual Allocations	100.00%	100.00%
Mid-point of Target Allocation Range	100.00%
Fair value of plan assets	$ 263.6	$ 238.0	$ 269.7
Actual return on plan assets	$ 35.7	$ (14.8)
United States \| Fixed income common trust funds
Employee benefit plans
Actual Allocations	67.00%	70.00%
Mid-point of Target Allocation Range	65.00%
United States \| Commingled global fund allocations
Employee benefit plans
Actual Allocations	17.00%	11.00%
Mid-point of Target Allocation Range	18.00%
United States \| Non-U.S. Government securities
Employee benefit plans
Actual Allocations	0.00%	1.00%
Mid-point of Target Allocation Range	0.00%
United States \| Global equity common trust funds
Employee benefit plans
Actual Allocations	5.00%	6.00%
Mid-point of Target Allocation Range	5.00%
United States \| U.S. Government securities
Employee benefit plans
Actual Allocations	9.00%	10.00%
Mid-point of Target Allocation Range	10.00%
United States \| Short-term investments
Employee benefit plans
Actual Allocations	2.00%	2.00%
Mid-point of Target Allocation Range	2.00%
Foreign Plan
Employee benefit plans
Actual Allocations	100.00%	100.00%
Mid-point of Target Allocation Range	100.00%
Fair value of plan assets	$ 178.1	$ 159.2	$ 183.4
Actual return on plan assets	$ 19.4	$ (8.7)
Foreign Plan \| Fixed income common trust funds
Employee benefit plans
Actual Allocations	45.00%	39.00%
Mid-point of Target Allocation Range	39.00%
Foreign Plan \| Commingled global fund allocations
Employee benefit plans
Actual Allocations	37.00%	36.00%
Mid-point of Target Allocation Range	37.00%
Foreign Plan \| Global equity common trust funds
Employee benefit plans
Actual Allocations	10.00%	17.00%
Mid-point of Target Allocation Range	13.00%
Foreign Plan \| Short-term investments
Employee benefit plans
Actual Allocations	1.00%	1.00%
Mid-point of Target Allocation Range	4.00%
Foreign Plan \| Non-U.S. Government securities
Employee benefit plans
Actual Allocations	7.00%	7.00%
Mid-point of Target Allocation Range	7.00%