Income Taxes - Computation of U.S. Federal Income Tax Rate to Pretax Loss From Continuing Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Computed expected tax benefit	$ (4,270)	$ (8,822)
State tax benefit, net of federal effect	(217)	(1,557)
Increase in the valuation allowance	4,487	10,379
Provision for income taxes	$ 0us-gaap_IncomeTaxExpenseBenefit	$ 0us-gaap_IncomeTaxExpenseBenefit

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

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-Publisher FASB

-Name Accounting Standards Codification

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

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-Name Regulation S-X (SX)

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-Subparagraph 2

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