Principal Business Activity and Significant Accounting Policies (Details) distributionCenter in Thousands, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) distributionCenter location segment state	Dec. 31, 2023 USD ($)
Accounting Policies [Abstract]
Number of reportable segments | segment	2
Number of points of distribution (more than) | distributionCenter	60
Number of retail pharmacy locations (more than) | location	2,600
Number of states in which the entity provides veterinary services to pet owners | state	39
Other current assets held-for-sale	$ 3.6
Other current liabilities held-for-sale	$ 1.1
Asset charges		$ 7.7