Revenue from contracts with customers - contract balances (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Receivables	$ 728.2	$ 679.1
Receivable - increase (decrease)	49.1
Contract Asset	6.5	0.4
Contract asset increase (decrease)	6.1
Contract Liability	15.1	$ 15.1
Contract liability - increase (decrease)	0.0
Revenue recognized included in beginning balance	$ 12.0

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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- Definition

Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in measure of progress which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in measure of progress which (increases) decreases obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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- Definition

The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.

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No definition available.

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