Components of Basic and Diluted Loss Per Share (Parenthetical) (Detail) - shares	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Common shares outstanding	26,085,274	22,115,916
Warrants outstanding	3,924,441
Common shares and new creditor warrants outstanding	30,009,715
Out-of-the-money Warrants
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Warrants outstanding	5,062,089

Common stock shares and class of warrants or rights outstanding.

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- Definition

Schedule Of Earnings Per Share Basic And Diluted [Line Items]

+ References

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Number of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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