Convertible Notes - Capped Calls (Details) - Capped Call [Member] $ in Millions	Sep. 18, 2019 USD ($) $ / item
Derivative [Line Items]
Cap price (in dollars per unit)	15.86
Premium above the last reported sales price (as a percent)	75.00%
Sales price (in dollars per unit)	9.06
Premium paid for the purchase of the capped calls | $	$ 6.2