Reclassifications out of Accumulated Other Comprehensive Income (“AOCI”) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
AOCI Net of Tax [Roll Forward]
Beginning balance	$ 3,472.8	$ 2,576.5	$ 3,509.1	$ 3,225.3
Other comprehensive (loss)/income before reclassification adjustments	914.4	313.3	719.2	(606.5)
Tax effect	(194.9)	(51.2)	(164.8)	134.5
Reclassification adjustments to net earnings	4.0	14.1	8.1	18.8
Tax effect	(0.9)	(3.0)	(1.9)	(4.0)
Ending balance	4,319.6	2,986.7	4,319.6	2,986.7
AOCI
AOCI Net of Tax [Roll Forward]
Beginning balance	(2,467.8)	(2,724.1)	(2,305.8)	(1,993.7)
Ending balance	(1,745.2)	(2,450.9)	(1,745.2)	(2,450.9)
Currency Translation Adjustment
AOCI Net of Tax [Roll Forward]
Beginning balance	(385.4)	(438.9)	(340.8)	(354.2)
Other comprehensive (loss)/income before reclassification adjustments	53.9	71.1	9.3	(13.6)
Tax effect	0.0	0.0	0.0	0.0
Reclassification adjustments to net earnings	0.0	0.0	0.0	0.0
Tax effect	0.0	0.0	0.0	0.0
Ending balance	(331.5)	(367.8)	(331.5)	(367.8)
Net Gains/Losses on Available-for-sale Securities
AOCI Net of Tax [Roll Forward]
Beginning balance	(1,824.6)	(1,978.1)	(1,705.6)	(1,330.0)
Other comprehensive (loss)/income before reclassification adjustments	860.5	242.2	709.9	(592.9)
Tax effect	(194.9)	(51.2)	(164.8)	134.5
Reclassification adjustments to net earnings	2.0	11.5	4.0	13.0
Tax effect	(0.5)	(2.7)	(1.0)	(2.9)
Ending balance	(1,157.5)	(1,778.3)	(1,157.5)	(1,778.3)
Cash Flow Hedging Activities
AOCI Net of Tax [Roll Forward]
Beginning balance	(22.5)	(25.8)	(23.3)	(26.6)
Other comprehensive (loss)/income before reclassification adjustments	0.0	0.0	0.0	0.0
Tax effect	0.0	0.0	0.0	0.0
Reclassification adjustments to net earnings	1.1	1.1	2.2	2.2
Tax effect	(0.2)	(0.2)	(0.5)	(0.5)
Ending balance	(21.6)	(24.9)	(21.6)	(24.9)
Pension Liability
AOCI Net of Tax [Roll Forward]
Beginning balance	(235.3)	(281.3)	(236.1)	(282.9)
Other comprehensive (loss)/income before reclassification adjustments	0.0	0.0	0.0	0.0
Tax effect	0.0	0.0	0.0	0.0
Reclassification adjustments to net earnings	0.9	1.5	1.9	3.6
Tax effect	(0.2)	(0.1)	(0.4)	(0.6)
Ending balance	$ (234.6)	$ (279.9)	$ (234.6)	$ (279.9)