Debt - Additional Information (Details) - USD ($)			1 Months Ended	3 Months Ended	9 Months Ended
	Mar. 03, 2017	Aug. 21, 2013	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2018	Apr. 01, 2017	Jul. 01, 2017	Mar. 22, 2017
Debt details
Loss on extinguishment of debt					$ 4,100,000	$ 0
0.625% Senior Convertible Notes | Convertible Notes
Debt details
Interest rate on senior convertible notes		0.625%		0.625%	0.625%
Aggregate principal amount of convertible debt		$ 650,000,000.0
Proceeds from debt, net of issuance costs		$ 636,300,000
Discount rate		5.40%
Derivative, term of contract		5 years
Redemption percentage		100.00%
Expected remaining term					4 months 15 days
Principal amount of debt repurchased				$ 22,500,000	$ 181,500,000
Cash paid for repurchase of debt				23,100,000	198,000,000
Loss on extinguishment of debt				300,000	4,100,000
Amount outstanding				428,500,000	428,500,000		$ 610,000,000
Fair market value of convertible debt				$ 436,300,000	$ 436,300,000		676,100,000
1.00% Senior Convertible Notes | Convertible Notes
Debt details
Interest rate on senior convertible notes				1.00%	1.00%
Aggregate principal amount of convertible debt	$ 400,000,000							$ 60,000,000
Proceeds from debt, net of issuance costs			$ 451,100,000
Discount rate	4.80%
Derivative, term of contract	7 years
Amount outstanding				$ 460,000,000	$ 460,000,000		460,000,000
Fair market value of convertible debt				$ 467,300,000	$ 467,300,000		$ 481,700,000