Stockholders' Equity - Summary of Non-Vested Stock Options (Detail) (USD $)	6 Months Ended
	Jun. 30, 2013
Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Number Of Shares [Roll Forward]
Nonvested at Beginning of period	853,640
Granted	116,242
Vested	(240,175)
Forfeited	(153,281)
Nonvested at End of period	576,426
Weighted Average Grant Date Fair Value, Nonvested at June 30, 2013	$ 2.24
Nonvested at June 30, 2013, Aggregate Intrinsic Value	$ 559,873