Revenue - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Disaggregation of Revenue
Customer revenue transferred over-time			24.90%	25.70%
Total net sales	$ 145,766	$ 200,933	$ 274,541	$ 351,402
Contract with customer, assets	33,606		33,606		$ 37,032
Contract with customer, liability	4,967		4,967		$ 4,472
Contract assets transferred to receivables			20,628
Cash proceeds from liability contract			2,751
Revenue recognized from contract liability	$ 1,237	$ 318	3,851	1,266
Over time
Disaggregation of Revenue
Customer revenue transferred over-time	24.40%	24.20%
Total net sales	$ 35,546	$ 48,595	68,323	90,343
Over time | Performance Based
Disaggregation of Revenue
Total net sales	24,858	34,984	49,290	66,821
Over time | Delivery Based
Disaggregation of Revenue
Total net sales	$ 10,688	$ 13,611	$ 19,033	$ 23,522
Point in time
Disaggregation of Revenue
Customer revenue transferred over-time	75.60%	75.80%	75.10%	74.30%
Total net sales	$ 110,220	$ 152,338	$ 206,218	$ 261,059