Financial Statements Details - Contract Balances (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Change in Contract with Customer, Asset [Roll Forward]
Contract assets, beginning balance	$ 0
Contract assets, ending balance	6,341
Change in Contract with Customer, Liability [Roll Forward]
Contract liabilities, beginning balance	16,521
Less: Revenue recognized from beginning balance	(7,561)
Less: Beginning balance reclassified to deferred revenue	(371)
Add: Contract liabilities recognized	24,006
Contract liabilities, ending balance	32,595
Other Current Liabilities
Change in Contract with Customer, Liability [Roll Forward]
Contract liabilities, ending balance	$ 13,500