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Restructuring Costs (Restructuring Activities) (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2021 | Dec. 31, 2020
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | $ 81 | $ 102
Amounts Accrued | 35 | 89
Cash Paid | (66) | (100)
Non-Cash/Other | (4) | (10)
Liability at end of period | 46 | 81
Severance |  |
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | 36 | 51
Amounts Accrued | 13 | 39
Cash Paid | (35) | (54)
Non-Cash/Other | 0 | 0
Liability at end of period | 14 | 36
Future rent under non-cancelable leases and other costs |  |
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | 45 | 51
Amounts Accrued | 22 | 50
Cash Paid | (31) | (46)
Non-Cash/Other | (4) | (10)
Liability at end of period | 32 | 45
Jardine Lloyd Thompson Group plc |  |
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | 25 | 47
Amounts Accrued | 61 | 251
Cash Paid | (58) | (226)
Non-cash charges | (13) | (47)
Liability at end of period | 15 | 25
Jardine Lloyd Thompson Group plc | Severance |  |
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | 16 | 42
Amounts Accrued | 9 | 43
Cash Paid | (15) | (69)
Non-cash charges | 0 | 0
Liability at end of period | 10 | 16
Jardine Lloyd Thompson Group plc | Real estate related costs |  |
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | 7 | 5
Amounts Accrued | 19 | 69
Cash Paid | (9) | (25)
Non-cash charges | (13) | (42)
Liability at end of period | 4 | 7
Jardine Lloyd Thompson Group plc | Information Technology |  |
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | 2 | 0
Amounts Accrued | 15 | 62
Cash Paid | (16) | (55)
Non-cash charges | 0 | (5)
Liability at end of period | 1 | 2
Jardine Lloyd Thompson Group plc | Consulting and other outside services |  |
Restructuring Reserve [Roll Forward] |  |
Liability at beginning of period | 0 | 0
Amounts Accrued | 18 | 77
Cash Paid | (18) | (77)
Non-cash charges | 0 | 0
Liability at end of period | $ 0 | $ 0

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- Definition Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 17 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3367-108585 + Details
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- Definition Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109237686&loc=d3e17752-110868 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.P.3) -URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(b)(1)) -URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747 + Details
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- Definition Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 5.P.4(b)(2)) -URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747 + Details
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