Note Income taxes (Reconciliation of unrecognized tax benefits) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure
Beginning Balance	$ 7.3	$ 7.4
Addition for tax positions	1.1	1.1
Reduction as a result of lapse of statute of limitations	(1.2)	(0.9)
Reduction as a result of settlements		(0.3)
Ending Balance	$ 7.2	$ 7.3

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Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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