CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Restricted Cash [Abstract]
Cash and cash equivalents		$ 476,782	$ 850,587	$ 778,967	$ 750,887
Restricted cash included in prepaid expenses and other current assets		498	498	315	1,534
Restricted cash included in other non-current assets		0	0	239	236
Cash, cash equivalents and restricted cash	[1]	$ 477,280	$ 851,085	$ 779,521	$ 752,657

[1] The following table provides a reconciliation of cash, cash equivalents and restricted cash shown above to amounts reported within the condensed consolidated balance sheets as of September 30, 2021, December 31, 2020, September 30, 2020 and December 31, 2019 (in thousands): September 30, 2021December 31, 2020September 30, 2020December 31, 2019Cash and cash equivalents$476,782 $850,587 $778,967 $750,887 Restricted cash included in prepaid expenses and other current assets498 498 315 1,534 Restricted cash included in other non-current assets— — 239 236 Cash, cash equivalents and restricted cash$477,280 $851,085 $779,521 $752,657