Convertible Note Purchase Agreement - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2015	Apr. 02, 2015
Short Term Debt [Line Items]
Debt Instrument, Face Amount		$ 15
Debt Instrument, Interest Rate, Stated Percentage		6.00%
Debt Conversion, Description	the Holder has the right, at its option, to convert the principal amount of the Note or any portion of such principal amount which is $1,000 or an integral multiple of $1,000 in excess thereof, into shares of common stock at the applicable conversion rate. The conversion rate is initially 869.57 shares of common stock per $1,000 principal amount of Note (equivalent to an initial conversion price of approximately $1.15 per share),
Letter of Credit [Member]
Short Term Debt [Line Items]
Debt Instrument, Face Amount	$ 15

The name of the original debt issue that has been converted in a noncash (or part noncash) transaction during the accounting period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	na
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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.

+ Details

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- Details

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