Segments - Assets by Reportable Segments (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Assets not allocated:
Cash and cash equivalents	$ 352.8	$ 346.1	$ 456.1
Income tax receivables	27.6	44.9
Other receivables	92.2	94.2
Advances and deposits	69.7	72.8
Deferred taxes	130.7	130.8
Total assets	7,199.3	7,200.6
Assets allocated to segments:
Assets allocated to segments:
Assets allocated to segments	6,059.2	6,049.8
Assets allocated to segments: | Food
Assets allocated to segments:
Assets allocated to segments	3,396.6	3,386.4
Assets allocated to segments: | Protective
Assets allocated to segments:
Assets allocated to segments	2,662.6	2,663.4
Assets not allocated:
Assets not allocated:
Cash and cash equivalents	352.8	346.1
Income tax receivables	27.6	44.9
Other receivables	92.2	94.2
Advances and deposits	69.7	72.8
Deferred taxes	130.7	130.8
Other	467.1	462.0
Total assets	$ 7,199.3	$ 7,200.6