Commitment and Contingencies - Capital Commitments (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Capital Commitments for Intangibles Not Yet Contracted
Other Commitments [Line Items]
Capital commitments	$ 3.0	$ 3.6	$ 4.8
Capital Commitments for Property and Equipment
Other Commitments [Line Items]
Capital commitments	1.8	2.8	1.0
Capital Commitments for Intangible Assets
Other Commitments [Line Items]
Capital commitments	$ 0.9	$ 1.3	$ 1.4