Business Combinations (Schedule of Purchase Price Allocation) (Details) - USD ($) $ in Millions	Mar. 20, 2023	Jan. 22, 2023	Jan. 03, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Liabilities assumed:
Goodwill acquired on acquisition				$ 4,537.0	$ 948.8	$ 947.7
IAA
Business Acquisition [Line Items]
Total cash consideration paid	$ 1,714.2	$ 1,700.0
Total fair value of consideration transferred	6,646.1
Assets acquired:
Cash and cash equivalents	166.6
Trade and other receivables, and other current assets	496.8
Inventory	57.1
Other current assets	28.0
Income taxes receivable	0.6
Property, plant and equipment	618.5
Operating lease right-of-use assets	1,281.0
Other non-current assets	34.8
Intangible assets	2,712.1
Liabilities assumed:
Auction proceeds payable	60.7
Trade and other liabilities	258.4
Current operating lease liability	75.2
Income taxes payable	3.7
Long-term operating lease liability	1,186.3
Other non-current liabilities	23.8
Deferred tax liabilities	688.5
Fair value of identifiable net assets acquired	3,098.9
Goodwill acquired on acquisition	$ 3,547.2
VeriTread
Business Acquisition [Line Items]
Total cash consideration paid			$ 28.1
Fair value of previously held interest			4.3
Total fair value of consideration transferred			32.4
Assets acquired:
Cash and cash equivalents			3.4
Trade and other receivables, and other current assets			0.9
Intangible assets			14.7
Liabilities assumed:
Trade and other liabilities			1.1
Fair value of identifiable net assets acquired			17.9
Redeemable non-controlling interest			(8.9)
Non-controlling interest			(1.8)
Goodwill acquired on acquisition			$ 25.2