Revenue - Schedule of Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Deferred Revenue Disclosure [Abstract]
Balance, beginning of the period	$ 8,687	$ 8,773	$ 8,080	$ 7,206
Deferral of revenue	6,130	1,601	11,631	6,154
Recognition of deferred revenue	(5,468)	(1,575)	(10,362)	(4,561)
Balance, ending of the period	$ 9,349	$ 8,799	$ 9,349	$ 8,799

Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in measure of progress which (increases) decreases obligation to transfer good or service to customer for which consideration from customer has been received or is due.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045

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