Goodwill and other intangibles - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Acquired Finite-Lived Intangible Assets [Line Items]
Tax-deductible goodwill	$ 18.0	$ 128.9
Measurement period to provisional purchase accounting adjustments	1 year	1 year
Amortization expense of other intangibles	$ 34.6	$ 33.0
Future amortization expense
Expected amortization expense in 2024	31.2
Expected amortization expense in 2025	27.4
Expected amortization expense in 2026	21.3
Expected amortization expense in 2027	12.8
Expected amortization expense in 2028	11.3
Title
Acquired Finite-Lived Intangible Assets [Line Items]
Other intangibles acquired	$ 28.7	12.6
Intangible assets, written off related to disposal of a business		$ 10.5

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of divestiture of an asset lacking physical substance and having a projected indefinite period of benefit to fair value. Excludes financial assets and goodwill.

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