Notes Payable - Capped Calls (Details) - Capped calls $ / shares in Units, $ in Millions	1 Months Ended
	May 31, 2018 USD ($) $ / shares shares
Capped calls
Initial strike price (in dollars per share)	$ 70.90
Initial cap price (in dollars per share)	$ 105.04
Number of shares covered | shares	7,757,158
Net cost to purchase the transactions | $	$ 58.5