Revenues - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase (decrease) in retained earnings	$ 450,876	$ 518,004
Contract with customer, deferred revenues	77,648	70,070	$ 72,358
Contract with customer, deferred revenues, current	53,371	54,255
Contract with customer, deferred revenues, noncurrent	24,200
Deferred sales commission	5,800	3,400	2,900
Sales commissions	16,300	$ 19,000	$ 20,300
Service-Type Warranties [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with customer, deferred revenues	10,400
Contract with customer, deferred revenues, current	3,600
Contract with customer, deferred revenues, noncurrent	$ 6,800
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase (decrease) in retained earnings				$ 2,600