Revenue from contracts with customers - Receivables and Contract Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Accounts receivables, net	$ 146.7	$ 150.9
Current contract liabilities (deferred revenues)	3.0	4.0
Non-current contract liabilities (deferred revenues)	$ 0.0	$ 2.4

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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Balance Type:	debit
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