Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2017

Prepaid Expenses And Other Assets [Abstract]

Prepaid Expenses And Other Current Assets

	December31, 2017	December31, 2016
Prepaid voyage costs	$                       14	$                       27
Inventory	220	220
Other	671	1,353
Total prepaid expenses and other current assets	$               905	$               1,600