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Goodwill and intangible assets - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Oct. 10, 2017
Indefinite-lived Intangible Assets [Line Items] |  |  |  |
Goodwill | $ 49,464 | $ 856 |  | $ 48,609
Amortization of Intangible Assets | 1,107 | $ 488 | $ 512 |
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months | 3,000 |  |  |
Finite-Lived Intangible Assets, Amortization Expense, Year Two | 3,000 |  |  |
Finite-Lived Intangible Assets, Amortization Expense, Year Three | 3,000 |  |  |
Finite-Lived Intangible Assets, Amortization Expense, Year Four | 3,000 |  |  |
Finite-Lived Intangible Assets, Amortization Expense, Year Five | 3,000 |  |  |
Finite-Lived Intangible Assets, Amortization Expense, after Year Five | 17,400 |  |  |
Polar Technologies, LLC [Member] |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |
Goodwill |  |  |  | 400
Supplier [Member] |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |
Goodwill |  |  |  | $ 400
Airgas Refrigerants, Inc. [Member] |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |
Goodwill | $ 48,600 |  |  |

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- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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- Definition Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References No definition available. + Details
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- Definition Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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- Definition Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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