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Balance Sheet Components - Narrative (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]    
Weighted average days to maturity 291 days  
Work-in-process inventories $ 0 $ 0
Depreciation and amortization $ 712,000,000 $ 517,000,000