Additional Cash Flow Information (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 6,275,698	$ 5,988,187	$ 5,358,087	$ 3,109,322
Cash, cash equivalents and restricted cash per condensed consolidated statement of cash flows	6,280,213	5,988,845	5,360,985	3,120,681
Prepaid expenses and other current assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents	4,515	658	2,898	8,004
Other assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents	$ 0	$ 0	$ 0	$ 3,355