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Stock-based compensation - Schedule of PU activity (Detail) | 12 Months Ended
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Dec. 31, 2021 $ / shares shares | Dec. 31, 2020 $ / shares shares | Dec. 31, 2019 $ / shares shares
Weighted Average Grant Date Fair Value |  |  |
Outstanding weighted average grant date fair value, beginning balance | $ / shares | $ 34.56 |  |
Outstanding weighted average grant date fair value, ending balance | $ / shares |  | $ 34.56 |
Maximum shares eligible to receive |  |  |
Outstanding maximum shares eligible to receive, beginning balance | 4,876,196 | 6,058,464 |
Outstanding maximum shares eligible to receive, ending balance |  | 4,876,196 | 6,058,464
Performance Units |  |  |
Number of Performance Units |  |  |
Outstanding number of shares (Units), beginning balance | 4,876,196 | 6,058,464 | 3,712,402
Granted, number of shares (Units) | 1,340,877 | 1,253,766 | 1,579,109
Vested, number of shares (Units) | (1,784,140) | (1,496,377) | (3,276)
Forfeited, number of shares (Units) | (258,258) | (539,670) | (248,031)
Adjustment upon final determination of level of performance goal achievement | 408,480 | (399,987) | 1,018,260
Outstanding number of shares (Units), ending balance | 4,583,155 | 4,876,196 | 6,058,464
Expected to vest, number of shares (Units) | 4,263,803 | 4,573,356 | 5,507,640
Weighted Average Grant Date Fair Value |  |  |
Outstanding weighted average grant date fair value, beginning balance | $ / shares | $ 34.56 | $ 31.07 | $ 28.40
Granted, weighted average grant date fair value | $ / shares | 44.06 | 42.49 | 34.68
Vested, weighted average grant date fair value | $ / shares | 30.66 | 25.21 | 27.47
Forfeited, weighted average grant date fair value | $ / shares | 39.97 | 33.77 | 29.04
Adjustment upon final determination of level of performance goal achievement | $ / shares | 43.99 | 42.60 | 34.72
Outstanding weighted average grant date fair value, ending balance | $ / shares | $ 39.40 | $ 34.56 | $ 31.07
Maximum shares eligible to receive |  |  |
Outstanding maximum shares eligible to receive, beginning balance | 4,876,196 | 6,058,464 | 3,712,402
Granted, maximum shares eligible to receive | 2,681,754 | 2,507,532 | 3,158,218
Vested, maximum shares eligible to receive | (1,784,140) | (1,496,377) | (3,276)
Forfeited, maximum shares eligible to receive | (320,098) | (560,867) | (278,755)
Adjustment upon final determination of level of performance goal achievement | (870,557) | (1,632,556) | (530,125)
Outstanding maximum shares eligible to receive, ending balance | 4,583,155 | 4,876,196 | 6,058,464
Net settlement on vesting of performance units (Note 18) (in shares) | 1,102,440 | 902,532 | 2,151
Increase due to achievement of higher-than-target performance (in percentage) | 31.20% |  | 66.67%
Decrease due to achievement of lower-than-target performance (in percentage) |  | 0.3298 |

X
- Definition Shares awarded to employees, net of shares for the payment of withholding taxes for meeting certain performance targets. This element is to be used only if shares are used in lieu of cash to satisfy all or a portion of withholding taxes. + References No definition available. + Details
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- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options [Abstract] + References No definition available. + Details
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- Definition Represents the maximum number of shares which the employer would have been required to issue upon the satisfaction of the performance condition, had these been not forfeited in the current reporting period. + References No definition available. + Details
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- Definition Represents the maximum number of shares to be issued to the employee, against the performance awards granted during the reporting period, upon the fulfillment of the performance condition. + References No definition available. + Details
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- Definition Share based compensation arrangement by share-based payment award equity instruments other than options increase decrease in shares upon final determination of level of performance goal achievement, performance number of shares. + References No definition available. + Details
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- Definition Represents the maximum number of shares to be issued to the employee against the outstanding performance awards, upon the fulfillment of performance condition. + References No definition available. + Details
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- Definition Represents the maximum number of shares which the employer would have issued upon the satisfaction of the maximum level specified performance target. + References No definition available. + Details
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- Definition As of the balance sheet date, the number of shares expected to be issued in future for awards (other than stock options) expected to vest. + References No definition available. + Details
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- Definition It represents the achievement of lower than maximum performance of Share Based Payment Award other than options. + References No definition available. + Details
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- Definition Share Based Compensation Arrangement By Share Based Payment Award Other Than Options Percentage Decrease In Target Shares Higher Than Target Performance + References No definition available. + Details
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- Definition Share based compensation arrangement by share base payment award other than options, percentage increase in target shares, higher than target performance. + References No definition available. + Details
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- Definition The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan). + References No definition available. + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(3) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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