Significant Balance Sheet Components - Accounts Receivable, Net and Prepaid Expenses and Other Current Assets and Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Net
Allowance for doubtful accounts	$ (412)	$ (425)
Accounts receivable, net	58,815	60,994
Prepaid expenses and other current assets
Accounts Receivable, Net
Prepaid Royalties	6,300	3,800
Other assets
Accounts Receivable, Net
Prepaid Royalties	3,000	3,400
Billed
Accounts Receivable, Net
Accounts receivable	57,184	60,037
Unbilled
Accounts Receivable, Net
Accounts receivable	$ 2,043	$ 1,382