Long-term debt - Schedule of Total Leverage Ratios (Details)	Jun. 11, 2020
Fiscal quarter ending September 30, 2020 through and including fiscal quarter ending December 31, 2021
Debt Instrument [Line Items]
Covenant requirement, maximum total leverage ratio	5.50
Fiscal quarter ending March 31, 2022
Debt Instrument [Line Items]
Covenant requirement, maximum total leverage ratio	5.25
Fiscal quarter ending June 30, 2022
Debt Instrument [Line Items]
Covenant requirement, maximum total leverage ratio	5.00
Fiscal quarter ending September 30, 2022
Debt Instrument [Line Items]
Covenant requirement, maximum total leverage ratio	4.75
Thereafter
Debt Instrument [Line Items]
Covenant requirement, maximum total leverage ratio	4.50