Fair Value - Assumptions Used for Estimating Fair Value of Level 3 Liabilities (Detail)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate	0.07%
Expected life of option (years)	8 months 12 days
Expected volatility of stock	39.91%	70.00%
Dividend yield	0.00%	0.00%
Minimum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate		0.11%
Expected life of option (years)		9 months
Maximum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk-free interest rate		1.32%
Expected life of option (years)		4 years 1 month 6 days

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

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Risk-free interest rate assumption used in valuing an instrument.

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