Other Comprehensive Income (Loss) - Schedule of Component of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
AOCI Attributable to Parent [Abstract]
Beginning balance	$ 10,771.9
Other comprehensive income (loss) before reclassifications	(98.6)	$ (518.2)	$ 247.7
Net amount reclassified from accumulated other comprehensive loss	103.7	35.8	250.8
Other comprehensive income (loss), net of tax (Note 17)	5.1	(482.4)	498.5
Ending balance	14,192.1	10,771.9
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent [Abstract]
Beginning balance	(4,327.0)	(3,844.6)	(4,343.1)
Other comprehensive income (loss), net of tax (Note 17)	5.1	(482.4)	498.5
Ending balance	(4,321.9)	(4,327.0)	(3,844.6)
Foreign currency translation gains/losses
AOCI Attributable to Parent [Abstract]
Beginning balance	(1,819.0)	(1,874.2)	(1,550.2)
Other comprehensive income (loss) before reclassifications	(580.2)	78.9	(324.4)
Net amount reclassified from accumulated other comprehensive loss	9.6	(23.7)	0.4
Other comprehensive income (loss), net of tax (Note 17)	(570.6)	55.2	(324.0)
Ending balance	(2,389.6)	(1,819.0)	(1,874.2)
Net unrealized gains/losses on available-for-sale securities
AOCI Attributable to Parent [Abstract]
Beginning balance	(26.2)	(37.1)	3.7
Other comprehensive income (loss) before reclassifications	(5.0)	10.1	(52.2)
Net amount reclassified from accumulated other comprehensive loss	(0.5)	0.8	11.4
Other comprehensive income (loss), net of tax (Note 17)	(5.5)	10.9	(40.8)
Ending balance	(31.7)	(26.2)	(37.1)
Retirement benefit plans
AOCI Attributable to Parent [Abstract]
Beginning balance	(2,697.3)	(2,062.3)	(2,583.6)
Other comprehensive income (loss) before reclassifications	424.6	(686.9)	291.5
Net amount reclassified from accumulated other comprehensive loss	94.0	51.9	229.8
Other comprehensive income (loss), net of tax (Note 17)	518.6	(635.0)	521.3
Ending balance	(2,178.7)	(2,697.3)	(2,062.3)
Net unrealized gains/losses on cash flow hedges
AOCI Attributable to Parent [Abstract]
Beginning balance	215.5	129.0	(213.0)
Other comprehensive income (loss) before reclassifications	62.0	79.7	332.8
Net amount reclassified from accumulated other comprehensive loss	0.6	6.8	9.2
Other comprehensive income (loss), net of tax (Note 17)	62.6	86.5	342.0
Ending balance	$ 278.1	$ 215.5	$ 129.0