Reclassification out of Accumulated Other Comprehensive Income "AOCI" (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Other comprehensive income (loss), net	$ 25.4	$ 242.5	$ 422.5
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive, beginning balance	5,752.2
Other comprehensive income/(loss) before reclassification adjustments	10.3	348.1	515.5
Tax effect	14.4	(86.9)	(124.4)
Reclassification adjustments to net earnings	1.8	(24.7)	41.2
Tax effect	(1.1)	6.0	(9.8)
Accumulated Other Comprehensive, ending balance	5,670.1	5,752.2
Prior service credits recognized		17.0
Accumulated Other Comprehensive (Loss) /Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive, beginning balance	(14.8)	(257.3)	(679.8)
Accumulated Other Comprehensive, ending balance	10.6	(14.8)	(257.3)
Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive, beginning balance	(322.2)	(269.2)	(227.0)
Other comprehensive income/(loss) before reclassification adjustments	95.4	(53.0)	(42.2)
Tax effect	0.0	0.0	0.0
Reclassification adjustments to net earnings	0.0	0.0	0.0
Tax effect	0.0	0.0	0.0
Accumulated Other Comprehensive, ending balance	(226.8)	(322.2)	(269.2)
Net Gains on Available-for-sale Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive, beginning balance	680.4	224.6	(274.0)
Other comprehensive income/(loss) before reclassification adjustments	(363.3)	602.2	642.4
Tax effect	82.6	(136.4)	(144.4)
Reclassification adjustments to net earnings	(11.3)	(12.9)	0.9
Tax effect	2.5	2.9	(0.3)
Accumulated Other Comprehensive, ending balance	390.9	680.4	224.6
Cash Flow Hedging Activities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive, beginning balance	(30.3)	0.0	0.0
Other comprehensive income/(loss) before reclassification adjustments	(3.3)	(40.3)	0.0
Tax effect	0.8	10.0	0.0
Reclassification adjustments to net earnings	3.8	0.0	0.0
Tax effect	(0.9)	0.0	0.0
Accumulated Other Comprehensive, ending balance	(29.9)	(30.3)	0.0
Pension Liability
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive, beginning balance	(342.7)	(212.7)	(178.8)
Other comprehensive income/(loss) before reclassification adjustments	281.5	(160.8)	(84.7)
Tax effect	(69.0)	39.5	20.0
Reclassification adjustments to net earnings	9.3	(11.8)	40.3
Tax effect	(2.7)	3.1	(9.5)
Accumulated Other Comprehensive, ending balance	$ (123.6)	$ (342.7)	$ (212.7)