Fair Value Measurement - Summary of Fair Value Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative asset - embedded conversion feature	$ 80,651
Derivative liability - embedded conversion feature		$ 120,848
Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative asset - embedded conversion feature	$ 80,651
Derivative liability - embedded conversion feature		$ 120,848

Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as an asset.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624163-113959

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- Definition

Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as a liability.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Details

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