Accounts Receivable (Schedule of Accounts Receivable) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Receivables [Abstract]
Trade and other accounts receivable	$ 165,005	$ 167,370
Bank promissory notes	26,837	24,860
Allowance for expected credit losses	(3,776)	(3,807)
Accounts receivable, net	$ 188,066	$ 188,423