Estimated Fair Value of the Embedded Derivative (Detail) (USD $)			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Derivative Liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)			$ 2,200,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings			2,046,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3			188,000
Estimated fair value of the embedded derivative	$ 3,680,000	$ 5,914,000