Fair Value Measurements - Fair Value of Convertible Senior Notes (Details) - Senior Notes - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Fair Value Disclosures [Line Items]
Fair value of outstanding senior convertible notes:	$ 2,537.0	$ 4,022.5
Senior Convertible Notes due 2023
Fair Value Disclosures [Line Items]
Fair value of outstanding senior convertible notes:	1,426.5	2,589.6
Senior Convertible Notes due 2025
Fair Value Disclosures [Line Items]
Fair value of outstanding senior convertible notes:	$ 1,110.5	$ 1,432.9