New Accounting Standards (Tables)

9 Months Ended

Sep. 30, 2018

New Accounting Standards [Abstract]

Reconciliation Of Cash, Cash Equivalents, And Restricted Cash

	September 30, 2018		December 31, 2017
	(in thousands)
Cash and cash equivalents	$	33,715	$	19,669
Restricted cash - current		1,025		842
Restricted cash - non-current		918		967
Abandonment funding		10,808		10,808
Total cash, cash equivalents and restricted cash shown in the condensed consolidated statements of cash flows	$	46,466	$	32,286