Supplemental Cash Flow Information (Supplemental Disclosures To The Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended
	Feb. 08, 2018	Mar. 31, 2018	Mar. 31, 2019
Supplemental cash flow information:
Cash paid for interest		$ 1,092	$ 3,527
Cash paid for income taxes, net of refunds		0	706
Non-cash investing and financing activities:
Increase in asset retirement obligations		421	314
Increase (decrease) in accruals or payables for capital expenditures		(37,152)	(96,865)
Increase in withholding tax accruals for share-based compensation		0	142,000
Distribution of non-STACK assets, net of liabilities		$ 0	$ 0
Predecessor
Supplemental cash flow information:
Cash paid for interest	$ 1,145
Cash paid for income taxes, net of refunds	0
Non-cash investing and financing activities:
Increase in asset retirement obligations	0
Increase (decrease) in accruals or payables for capital expenditures	4,896
Increase in withholding tax accruals for share-based compensation	0
Distribution of non-STACK assets, net of liabilities	$ 43,482