Income taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Income taxes
Effective income tax rate (as a percent)	26.70%	23.10%	27.00%	23.60%	23.70%	25.10%
Income tax benefit from loss on extinguishment of debt	$ 1.4
Effect of net operating loss carryback charges related to CARES Act			$ 1.6
Accrued liability, CARES Act	$ 2.7		$ 2.7

The amount of deferred liability at balance sheet date for employer payroll taxes accrued as a result of the CARES Act.

No definition available.

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- Definition

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to provisions of the CARES Act.

+ References

No definition available.

+ Details

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- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

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- Definition

Current period income tax expense or benefit pertaining to a gain (loss) on an extinguishment of debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12317-112629

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- References

No definition available.

+ Details

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