Balance Sheet Components - Inventories - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Realized benefit from sales of previously reserved products	$ 1.3	$ 1.3

Return of or reimbursements received in relation to direct costs and expenses previously paid or incurred.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Name:	us-gaap_RecoveryOfDirectCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration