Leases (Future Minimum Revenues on Charters-Out) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Operating Leases, Future Minimum Payments Receivable [Abstract]
2019, prior to ASC 842 adoption		$ 2,587
Future minimum revenues, prior to ASC 842 adoption		$ 2,587
2019, revenue days		221 days
Revenue Days		221 days
Charters-Out [Member]
Operating Leases, Future Minimum Payments Receivable [Abstract]
2019	$ 6,266
2020	698
Net minimum lease payments	$ 6,964
2019, revenue days	445 days
2020, revenue days	49 days
Revenue Days	494 days