Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2018
Foreign currency translation adjustments, tax expense (benefit)	$ 3.0	$ (2.6)
Prior service credit (cost), tax benefit	(0.1)	1.2
Net actuarial gain (loss), tax expense (benefit)	(34.6)	(15.7)
Derivative financial instrument, tax expense (benefit)	0.2	(0.1)
Dun & Bradstreet Corp
Prior service credit (cost), tax benefit	$ (0.2)
Net actuarial gain (loss), tax expense (benefit)		$ (6.7)

Amount of tax expense (benefit) 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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- Definition

Amount, after reclassification, of tax expense (benefit) for gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e640-108580

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Amount of tax expense (benefit), after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of tax (expense) benefit for 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).

+ References

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-Publisher FASB
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-Topic 220
-SubTopic 10
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