Revenue and Accounts Receivable - Contract Balances (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Contract with Customer, Asset, Net, Current [Roll Forward]
Contract with Customer, Receivable, Net, Current	$ 296,355	$ 309,075
Contract with Customer, Receivable, Current, Net Increase (Decrease)	(13,998)	(3,403)
Contract with Customer, Receivable, Net, Current	282,357	305,672
Contract with Customer, Asset, Gross, Current	31,525	2,833
Contract with Customer, Contract Asset, Current, Net Increase (Decrease)	(12,244)	(1,799)
Contract with Customer, Asset, Gross, Current	19,281	1,034
Contract with Customer, Asset, Net, Noncurrent [Roll Forward]
Contract with Customer, Receivable, Net, Noncurrent	63,554	60,948
Contract with Customer, Receivable, NonCurrent, Net Increase (Decrease)	(580)	3,628
Contract with Customer, Receivable, Net, Noncurrent	62,974	64,576
Contract with Customer, Asset, Gross, Noncurrent	2,504	541
Increase (Decrease) in Contract Receivables, Net	(88)	1,787
Contract with Customer, Asset, Gross, Noncurrent	2,416	2,328
Contract with Customer, Liability, Current [Roll Forward]
Contract with Customer, Liability, Current	2,492	4,016
Contract with Customer, Liability, Current, Net Increase (Decrease)	9,784	912
Contract with Customer, Liability, Current	12,276	4,928
Contract with Customer, Liability, Noncurrent [Roll Forward]
Contract with Customer, Liability, Noncurrent	615	1,731
Contract with Customer, Liability, Noncurrent, Net Increase (Decrease)	(234)	(1,116)
Contract with Customer, Liability, Noncurrent	$ 381	$ 615