Revenue Recognition - Additional Information (Details 1) $ in Thousands	Mar. 31, 2019 USD ($)
Revenue Recognition [Line Items]
Estimated revenue expected to be recognized in the future	$ 3,963
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Revenue Recognition [Line Items]
Estimated revenue expected to be recognized in the future	$ 1,392
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue Recognition [Line Items]
Estimated revenue expected to be recognized in the future	$ 1,603
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Recognition [Line Items]
Estimated revenue expected to be recognized in the future	$ 968
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year