Derivatives (Details) - 12 months ended Dec. 31, 2022 $ in Millions	USD ($)	EUR (€)
Derivative [Line Items]
Decrease in net investment hedges \| $	$ 82
Senior Notes \| JLT Transaction
Derivative [Line Items]
Debt instrument, face amount \| €		€ 1,100,000,000
Net investment hedge, threshold percentage of the equity balance	80.00%

Amount before tax and 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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 10
-Section 45
-Paragraph 9
-URI https://asc.fasb.org/extlink&oid=126980362&loc=d3e28129-110885

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 12
-URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32022-110900

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e637-108580

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669646-108580

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 35
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=123602790&loc=d3e30304-110892

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration