Stock-Based Compensation Arrangements (Non-vested options) (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Non-vested options, beginning of year	17,992,652	2,878,739
Non-vested options, beginning of year, Weighted Avg Exercise Price	$ 0.18	$ 0.37
Granted, Shares	10,622,392	18,193,027
Granted, Weighted Avg Exercise Price	$ 0.16	$ 0.17
Vested, Shares	(8,035,609)	(2,038,435)
Vested, Weighted Avg Exercise Price	$ 0.15	$ 0.33
Forfeited, Shares	(76,166)	(1,040,679)
Forfeited, Weighted Avg Exercise Price	$ 0.25	$ 0.17
Non-vested options, end of year, Shares	20,503,269	17,992,652
Non-vested options, end of year, Weighted Avg Exercise Price	$ 0.17	$ 0.18