Supplemental Disclosures of Cash Flow Information - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Supplemental Cash Flow Information [Abstract]
Cash paid for interest	$ 1,810	$ 868
Cash paid for income taxes	0	0
Cash paid for operating leases	311	229
Non-cash operating activities:
Operating leases	112	14,667
Non-cash investing and financing activities:
Accounts payable and accrued liabilities - oil and gas properties	58,384	92,702
Change in asset retirement obligations, net of disposals	(380)	933
Retirement of treasury stock	$ (636)	$ (1,484)