Stock-based Compensation Expense and Share Repurchase Programs - Unrecognized Stock-based Compensation Expense (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($)
Restricted stock units (including PSUs)
Type of award:
Unrecognized Expense	$ 473,493
Weighted-average Recognition Period	2 years 29 days
Stock options
Type of award:
Unrecognized Expense	$ 91,779
Weighted-average Recognition Period	2 years 1 month 24 days
ESPP share issuances
Type of award:
Unrecognized Expense	$ 6,489
Weighted-average Recognition Period	7 months 2 days