Assumptions used in Calculating Fair Value of Derivative Instrument Liabilities Measured with Level Three Inputs (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
October 2006
Fair Value Measurements [Line Items]
Annual volatility	44.80%	52.90%
Risk-free rate	0.14%	0.21%
Dividend rate	0.00%	0.00%
Closing price of Quantum stock	$ 0.62	$ 0.68
Conversion / exercise price	$ 0.62	$ 0.83
Feb 18, 2011
Fair Value Measurements [Line Items]
Annual volatility	50.20%	53.30%
Risk-free rate	0.36%	0.36%
Dividend rate	0.00%	0.00%
Closing price of Quantum stock	$ 0.62	$ 0.68
Conversion / exercise price	$ 6.00	$ 6.00
January 2013
Fair Value Measurements [Line Items]
Annual volatility	73.70%
Dividend rate	0.00%
Closing price of Quantum stock	$ 0.62
Conversion / exercise price	$ 1.00
Minimum | January 2013
Fair Value Measurements [Line Items]
Risk-free rate	0.07%
Maximum | January 2013
Fair Value Measurements [Line Items]
Risk-free rate	0.77%