CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Parenthetical - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Pension Plan and Restoration of Retirement Income Plan:
Amortization of deferred net loss	$ 0.2	$ 0.3
Postretirement Benefit Plans:
Amortization of prior service cost	(0.1)	(0.2)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Noncontrolling Interest	0.0	(0.4)
Pension Plan [Member]
Other Comprehensive Income (Loss), Defined Benefit Plan, Adjustment for Settlement or Curtailment Gain (Loss), Tax	$ 1.0	$ 0.0

-- None. No documentation exists for this element. --

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- Definition

Tax effect on adjustment out of other comprehensive income for prior service costs recognized as a component of net periodic postretirement benefit cost during the period.

+ References

No definition available.

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- Definition

Amount of tax expense (benefit) for increase (decrease) to other comprehensive income from settlement and curtailment gain (loss) of defined benefit plan.

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-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
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- Definition

Amount before tax of other comprehensive income (loss) attributable to noncontrolling interests.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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