Stock Based Awards and Other Equity Instruments - Summary of RSU Activity (Details) - Restricted Stock Units $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($) $ / shares shares
RSUs outstanding
Unvested outstanding, Beginning balance | shares	8,111
Unvested RSUs, Granted | shares	2,277
Unvested RSUs, Vested and released | shares	(2,963)	[1]
Unvested RSUs, Cancelled | shares	(666)
Unvested outstanding, Ending balance | shares	6,759
Weighted Average Grant-Date Fair Value Per Share
Unvested outstanding, Weighted Average Grant-Date Fair Value Per Share, Beginning balance | $ / shares	$ 32.29
Weighted Average Grant-Date Fair Value Per Share, Granted | $ / shares	45.77
Weighted Average Grant-Date Fair Value Per Share, Vested and released | $ / shares	33.15	[1]
Weighted Average Grant-Date Fair Value Per Share, Cancelled | $ / shares	34.90
Unvested outstanding, Weighted Average Grant-Date Fair Value Per Share, Ending balance | $ / shares	$ 36.19
Aggregate Intrinsic Value
Unvested RSUs outstanding, Aggregate Intrinsic Value | $	$ 273

[1] Inclusive of approximately 663,000 RSUs withheld due to net share settlement to satisfy required employee tax withholding requirements. Potential shares which were withheld in connection with settlement of RSUs to satisfy required employee tax withholding requirements remain in the authorized but unissued pool under the 2018 Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited condensed consolidated statements of cash flows.