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The earnings attributable to each security on the basis that all of the earnings for the period had been distributed (to the extent that each security may share in earnings). This is the earnings amount which reflects the participation rights in undistributed earnings of each security, after giving effect to all dilutive potential common shares outstanding during the period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent, and includes adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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The earnings that is allocated to common stock and participating securities to the extent that each security may share in earnings as if all of the earnings for the period had been distributed.

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Earnings (Loss) Per Share (Computation of Basic and Diluted Earnings per Common Share) (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended							5 Months Ended	7 Months Ended	12 Months Ended
	Jun. 30, 2018	Jun. 03, 2018	Dec. 31, 2018	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 03, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Successor
Basic Loss Per Share
Net income (loss)	$ 4,980		$ 43,732	$ 12,713							$ 61,425
Denominator:
Basic weighted average common shares outstanding (in shares)											20,028,227
Denominator:
Basic weighted average common shares outstanding (in shares)											20,028,227
Diluted weighted average shares outstanding (in shares)											20,164,638
Successor \| Basic Share
Basic Loss Per Share
Net income (loss)											$ 61,425
Undistributed Earnings, Basic											$ 61,425
Denominator:
Basic weighted average common shares outstanding (in shares)											20,028,000
Earnings Per Share, Diluted, Undistributed											$ 3.07
Denominator:
Basic weighted average common shares outstanding (in shares)											20,028,000
Successor \| Diluted Share
Basic Loss Per Share
Net income (loss)											$ 61,425
Net Income (Loss) Attributable to Parent, Diluted											$ 61,425
Denominator:
Basic weighted average common shares outstanding (in shares)											20,028,000
Earnings Per Share, Diluted, Undistributed											$ 3.05
Denominator:
Basic weighted average common shares outstanding (in shares)											20,028,000
Effect of dilutive options and warrants (in shares)											136,000
Diluted weighted average shares outstanding (in shares)											20,164,000
Predecessor
Basic Loss Per Share
Net income (loss)		$ 701,157			$ (5,001)	$ (206,116)	$ 1,274	$ 5,672	$ (7,395)	$ 696,156		$ (206,565)	$ (510,720)
Denominator:
Basic weighted average common shares outstanding (in shares)										29,338,329		29,306,374	29,270,455
Denominator:
Basic weighted average common shares outstanding (in shares)										29,338,329		29,306,374	29,270,455
Diluted weighted average shares outstanding (in shares)										29,338,329		29,306,374	29,270,455
Predecessor \| Basic Share
Basic Loss Per Share
Net income (loss)										$ 696,156		$ (206,565)	$ (510,720)
Undistributed Earnings, Basic										$ 696,156		$ (206,565)	$ (510,720)
Denominator:
Basic weighted average common shares outstanding (in shares)										29,338,000		29,306,000	29,270,000
Earnings Per Share, Diluted, Undistributed										$ 23.73		$ (7.05)	$ (17.45)
Denominator:
Basic weighted average common shares outstanding (in shares)										29,338,000		29,306,000	29,270,000
Predecessor \| Diluted Share
Basic Loss Per Share
Net income (loss)										$ 696,156		$ (206,565)	$ (510,720)
Net Income (Loss) Attributable to Parent, Diluted										$ 696,156		$ (206,565)	$ (510,720)
Denominator:
Basic weighted average common shares outstanding (in shares)										29,338,000		29,306,000	29,270,000
Earnings Per Share, Diluted, Undistributed										$ 23.73		$ (7.05)	$ (17.45)
Denominator:
Basic weighted average common shares outstanding (in shares)										29,338,000		29,306,000	29,270,000
Effect of dilutive options and warrants (in shares)										0		0	0
Diluted weighted average shares outstanding (in shares)										29,338,000		29,306,000	29,270,000