Accounts Receivable (Schedule of Changes in Allowance for Credit Losses for Noncurrent Receivables) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Noncurrent receivables expected credit losses at beginning	$ 0
Charges	190
Currency translation	9
Other	0
Noncurrent receivables expected credit losses at end	$ (387)	$ 0
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201602Member
Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Noncurrent receivables expected credit losses at beginning	$ (206)
Noncurrent receivables expected credit losses at end		$ (206)