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Employee and Agent Benefits - Pension Plan Changes and Plan Gains/Losses (Details) - Pension benefits - USD ($) $ in Millions		12 Months Ended
	May 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Components of Net Periodic Benefit Cost (Income)
Actuarial gain (loss)	$ (59.0)	$ (462.4)	$ (506.4)
Total plan amendment gain	122.4
Increase in benefit obligation	237.6
Asset gain on plan assets	$ 178.6	$ 521.3	$ 520.9

X

- Definition

Amount of defined benefit plan gain (loss) from effect of plan amendment, recorded in AOCI and amortized into earnings over time.

+ References

No definition available.

+ Details

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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

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- Definition

Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Amount of increase (decrease) in benefit obligation of defined benefit plan.

+ References

No definition available.

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- References

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