Revenues from Contracts with Customers - Contract Liabilities Rollforward (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Change In Contract With Customer, Liability [Roll Forward]
Contract with Customer, Liability	$ 4,652	$ 132
Sonneborn acquisition		6,463
Contract With Customer, Liability, Increase	16,115	10,813
Contract with Customer, Liability, Revenue Recognized	(14,980)	(12,906)
Contract with Customer, Liability	$ 5,787	$ 4,502