Derivative Financial Instruments - Significant Assumptions Utilized in Binomial Lattice Process (Detail) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Derivative [Line Items]
Linked common shares	1,562,500	1,562,500	1,562,500
Level 1 [Member]
Derivative [Line Items]
Linked common shares		1,725,000
Quoted market price on valuation date		$ 2.96
Contractual exercise rate		$ 2.4648
Term (years)		3 months 11 days
Level 2 [Member]
Derivative [Line Items]
Linked common shares		525,000	525,000
Quoted market price on valuation date		$ 2.96	$ 2.02
Contractual exercise rate		$ 2.4648	$ 2.3793
Term (years)		9 months 15 days	3 months 11 days
Level 3 [Member]
Derivative [Line Items]
Linked common shares	1,562,500	1,562,500	1,562,500
Quoted market price on valuation date	$ 1.68	$ 2.96	$ 2.02
Contractual exercise rate	$ 3.60	$ 3.60	$ 3.60
Term (years)	2 years 10 months 10 days	3 years 10 months 10 days	3 years 4 months 6 days
Custom lattice variable: Probability of exercisability (434,027 linked common shares)
Minimum [Member] | Level 1 [Member]
Derivative [Line Items]
Range of market volatilities		17.30%
Risk free rates using zero coupon US Treasury Security rates		0.02%
Minimum [Member] | Level 2 [Member]
Derivative [Line Items]
Range of market volatilities		31.70%	50.10%
Risk free rates using zero coupon US Treasury Security rates		0.02%	0.01%
Minimum [Member] | Level 3 [Member]
Derivative [Line Items]
Range of market volatilities	55.00%	44.30%	51.10%
Risk free rates using zero coupon US Treasury Security rates	0.04%	0.04%	0.07%
Custom lattice variable: Probability of exercisability (434,027 linked common shares)
Maximum [Member] | Level 1 [Member]
Derivative [Line Items]
Range of market volatilities		53.60%
Risk free rates using zero coupon US Treasury Security rates		0.04%
Maximum [Member] | Level 2 [Member]
Derivative [Line Items]
Range of market volatilities		53.50%	88.30%
Risk free rates using zero coupon US Treasury Security rates		0.10%	0.07%
Maximum [Member] | Level 3 [Member]
Derivative [Line Items]
Range of market volatilities	87.20%	62.30%	78.20%
Risk free rates using zero coupon US Treasury Security rates	0.47%	0.66%	0.78%
Custom lattice variable: Probability of exercisability (434,027 linked common shares)