Leases - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) ft²	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) ft²	Jun. 30, 2018 USD ($)
Operating Leased Assets [Line Items]
Operating lease right-of-use assets			$ 2,400
Operating lease, liability	$ 18,732		18,732
Lease expense for operating lease	1,300		2,600
Variable lease payments for operating lease	$ 500		$ 700
Operating leases, rent expense		$ 800		$ 1,400
Minimum
Operating Leased Assets [Line Items]
Term of contract	1 year		1 year
Maximum
Operating Leased Assets [Line Items]
Term of contract	18 years		18 years
North Carolina
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft) | ft²			61,000
California
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft) | ft²			37,300
New Jersey
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft) | ft²			34,000
Ireland
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft) | ft²	30,000
Right-of-use Asset and liability upon lease inception	$ 2,400		$ 2,400