Net Income (Loss) Per Share - Schedule of Computation of Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Basic net income (loss) per share:
Net income (loss) attributable to common stockholders	$ 63.6	$ (55.4)	$ 132.8	$ (105.2)
Shares used in computation:
Weighted-average common shares outstanding (in shares)	292,462,184	279,974,823	290,591,037	159,214,343
Basic net income (loss) per share (in dollars per share)	$ 0.22	$ (0.20)	$ 0.46	$ (0.66)
Diluted net income (loss) per share:
Net income (loss) attributable to common stockholders	$ 63.6	$ (55.4)	$ 132.8	$ (105.2)
Weighted-average effect of potentially dilutive securities:
Diluted weighted-average common shares outstanding (in shares)	347,886,695	279,974,823	344,994,314	159,214,343
Diluted net income (loss) per share (in dollars per share)	$ 0.18	$ (0.20)	$ 0.39	$ (0.66)
Employee stock options
Weighted-average effect of potentially dilutive securities:
Weighted-average effect of potentially dilutive securities (in shares)	54,271,831	0	53,426,104	0
Restricted stock units and awards
Weighted-average effect of potentially dilutive securities:
Weighted-average effect of potentially dilutive securities (in shares)	636,056	0	552,394	0
Shares estimated to be purchased under ESPP
Weighted-average effect of potentially dilutive securities:
Weighted-average effect of potentially dilutive securities (in shares)	516,624	0	424,779	0