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Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Beginning Balance | $ (1,090) |
Net unrealized gain (loss) | (34) | $ 102
Reclassification of net loss to net income | 8 | 8
Ending Balance | (733) | (1,090)
Accumulated Translation Adjustment [Member] |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Beginning Balance | (907) | (917)
Net unrealized gain (loss) | 348 | (18)
Repurchase of shares under normal course issuer bids [note 19] | 8 | 28
Ending Balance | (551) | (907)
Accumulated Net (Loss) Gain from Designated or Qualifying Cash Flow Hedges [Member] |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Beginning Balance | 38 | (68)
Net unrealized gain (loss) | (34) | 102
Reclassification of net loss to net income | 38 | 4
Ending Balance | 42 | 38
Accumulated Net Unrealized Loss On Other Long Term Liabilities [Member] |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Beginning Balance | (221) | (190)
Net unrealized loss | (11) | (47)
Reclassification of net loss to net income | 8 | 8
Sale of business |  | 8
Ending Balance | (224) | (221)
AOCL [Member] |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Beginning Balance | (1,090) |
Ending Balance | $ (733) | $ (1,090)

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- Definition Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(30)(a)(4)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(23)(a)(3)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (h)(2) -URI http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (g)(2)(ii) -URI http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e681-108580 + Details
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