Revenue - Additional Information (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($) segment	Jun. 30, 2018 USD ($)
Revenue From Contract With Customer [Abstract]
Contract acquisition cost recognition, description		most direct contract acquisition costs relate to contracts that are recognized over a period of one year or less.
Contract acquisition, capitalized cost	$ 0	$ 0
Number of reportable segment | segment		2
Estimated contracted revenue	105,200,000	$ 105,200,000
Revenue, remaining performance obligation, expected timing of satisfaction, Description		Revenue allocated to remaining performance obligations represents estimated contracted revenue that has not yet been recognized which includes unearned revenue and amounts that will be invoiced and recognized as revenue in future periods. Estimated contracted revenue was $105.2 million as of June 30, 2019 of which we expect to recognize approximately 81% over the next 12 months and the remainder thereafter.
Revenue remaining performance obligation percentage of revenue expected to be recognized		81.00%
Revenue recognized performance obligation	$ 5,300,000	$ 5,300,000
Contract with customer assets increase (decrease)		1,300,000
Decrease in deferred revenue		(14,611,000)	$ (3,387,000)
Deferred revenue increase decrease due to revenue recognized upon customer acceptance		$ 5,000,000.0