Description of Business and Significant Accounting Policies - Schedule of Cumulative Effect of Initially Applying New Guidance (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Assets
Short-term accounts and notes receivable, less allowance for doubtful accounts	$ 277,031		$ 340,930
Notes receivable – long–term portion, less allowance for doubtful accounts	39,458		46,992
Allowance for doubtful accounts on short-term accounts and notes receivables	(76,751)		(45,726)
Allowance for doubtful accounts on long-term notes receivables	(5,342)		(6,667)
Deferred income taxes	38,265		20,364
Stockholders’ equity
Retained earnings	$ 188,578		$ 195,455
Cumulative Impact from Adopting ASC 326 Guidance
Assets
Short-term accounts and notes receivable, less allowance for doubtful accounts		$ (41,100)
Notes receivable – long–term portion, less allowance for doubtful accounts		(1,136)
Allowance for doubtful accounts on short-term accounts and notes receivables		(41,100)
Allowance for doubtful accounts on long-term notes receivables		(1,136)
Deferred income taxes		10,137
Stockholders’ equity
Retained earnings		(32,099)
Balance, January 1, 2020
Assets
Short-term accounts and notes receivable, less allowance for doubtful accounts		299,830
Notes receivable – long–term portion, less allowance for doubtful accounts		45,856
Allowance for doubtful accounts on short-term accounts and notes receivables		(86,826)
Allowance for doubtful accounts on long-term notes receivables		(7,803)
Deferred income taxes		30,501
Stockholders’ equity
Retained earnings		$ 163,356