Revenue Recognition Disaggregation of Revenue by type of activity and reporting segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Inter-segment revenue elimination									$ (37.5)	$ (60.1)	$ (41.1)
Net revenue	$ 725.7	$ 617.5	$ 623.0	$ 551.8	$ 685.3	$ 627.9	$ 606.3	$ 543.9	2,518.0	2,463.4	2,075.4
Softgel Technologies [Member]
Disaggregation of Revenue [Line Items]
Net revenue									872.1	917.3	855.3
Softgel Technologies [Member] | Manufacturing & Commercial Product Supply [Member]
Disaggregation of Revenue [Line Items]
Net revenue									806.1
Softgel Technologies [Member] | Development Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									66.0
Softgel Technologies [Member] | Clinical Supply Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									0.0
Biologics and Specialty Drug Delivery [Member]
Disaggregation of Revenue [Line Items]
Net revenue									742.1	601.9	350.8
Biologics and Specialty Drug Delivery [Member] | Manufacturing & Commercial Product Supply [Member]
Disaggregation of Revenue [Line Items]
Net revenue									379.5
Biologics and Specialty Drug Delivery [Member] | Development Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									362.6
Biologics and Specialty Drug Delivery [Member] | Clinical Supply Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									0.0
Oral Drug Delivery [Member]
Disaggregation of Revenue [Line Items]
Net revenue									619.9	573.9	561.6
Oral Drug Delivery [Member] | Manufacturing & Commercial Product Supply [Member]
Disaggregation of Revenue [Line Items]
Net revenue									403.0
Oral Drug Delivery [Member] | Development Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									216.9
Oral Drug Delivery [Member] | Clinical Supply Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									0.0
Clinical Supply Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									321.4	$ 430.4	$ 348.8
Clinical Supply Services [Member] | Manufacturing & Commercial Product Supply [Member]
Disaggregation of Revenue [Line Items]
Net revenue									0.0
Clinical Supply Services [Member] | Development Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									0.0
Clinical Supply Services [Member] | Clinical Supply Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									321.4
Total Catalent before inter-segment revenue elimination [Member]
Disaggregation of Revenue [Line Items]
Net revenue									2,555.5
Total Catalent before inter-segment revenue elimination [Member] | Manufacturing & Commercial Product Supply [Member]
Disaggregation of Revenue [Line Items]
Net revenue									1,588.6
Total Catalent before inter-segment revenue elimination [Member] | Development Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									645.5
Total Catalent before inter-segment revenue elimination [Member] | Clinical Supply Services [Member]
Disaggregation of Revenue [Line Items]
Net revenue									$ 321.4