Accounts Receivable (Accounts Receivable) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Trade receivables	$ 361,656	$ 334,059
Allowance for doubtful accounts	(7,093)	(5,674)
Other allowances	(2,891)	(2,644)
Accounts receivable, net	$ 351,672	$ 325,741