Income tax expense - Deferred tax assets and liabilities (Detail) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Deferred tax assets: | ||
| Loss carryforwards | $ 135.9 | $ 163.3 |
| Capital loss carryforwards | 35.8 | 34.4 |
| Interest expense limitation carryforwards | 9.7 | 10.9 |
| Finance and share issuance costs | 0.1 | 0.5 |
| Tax Credits | 1.4 | 1.4 |
| Stock-based compensation | 2.4 | 2.9 |
| Derivative contracts | 5.7 | 3.2 |
| Other long-term notes | 1.5 | |
| Other | 0.9 | |
| Total deferred tax assets | 191.9 | 218.1 |
| Less: Valuation allowance | (145.4) | (139.7) |
| Net deferred tax assets | 46.5 | 78.4 |
| Deferred tax liabilities: | ||
| Intangible assets | (21.9) | (30.0) |
| Property, plant and equipment | (31.2) | (41.9) |
| Basis difference in joint ventures | (5.4) | (15.5) |
| Other long-term investments | (1.3) | |
| Total deferred tax liabilities | (59.8) | (87.4) |
| Net deferred tax liability | (13.3) | (9.0) |
| Net deferred tax asset | 9.0 | |
| US | ||
| Deferred tax liabilities: | ||
| Net deferred tax liability | (23.7) | (16.0) |
| Canada. | ||
| Deferred tax liabilities: | ||
| Net deferred tax asset | $ 10.4 | $ 7.0 |
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible Interest expense limitation carryforwards. No definition available.
|
| X | ||||||||||
- Definition The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to issuance costs which can only be realized if sufficient taxable income is generated in future periods to enable the deduction to be taken. No definition available.
|
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences related to other long-term notes. No definition available.
|
| X | ||||||||||
- Definition Amount of deferred tax liability attributable to taxable temporary differences from basis difference in joint ventures. No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of deferred tax liability attributable to taxable temporary differences. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible capital loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from derivative instruments. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of deferred tax liability attributable to taxable temporary differences from investments (excludes investments in subsidiaries and equity method investments). No definition available.
|
| X | ||||||||||
- Definition Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|