Revenue Recognition - Performance Obligation (Details) $ in Thousands	Jun. 30, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 5,567
Expected timing of satisfaction, period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 1,910
Expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 1,623
Expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 9,100
Expected timing of satisfaction, period
Product Sales [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 0
Expected timing of satisfaction, period	6 months
Product Sales [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 1,910
Expected timing of satisfaction, period	1 year
Product Sales [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 1,623
Expected timing of satisfaction, period	1 year
Product Sales [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 3,533
Expected timing of satisfaction, period
Research and Development Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 5,567
Expected timing of satisfaction, period	6 months
Research and Development Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 0
Expected timing of satisfaction, period	1 year
Research and Development Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 0
Expected timing of satisfaction, period	1 year
Research and Development Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligation	$ 5,567
Expected timing of satisfaction, period