Stock Compensaton - Stock Option Activity (Detail)	3 Months Ended
	Mar. 31, 2016 $ / shares shares
Number of Shares
Options outstanding, beginning balance (in shares) | shares	10,232,969
Granted (in shares) | shares	3,464,825
Forfeited (in shares) | shares	(201,147)
Exercised (in shares) | shares	(23,600)
Options outstanding, ending balance (in shares) | shares	13,473,047
Weighted Average Exercise Price Per Share
Options outstanding, beginning balance (in dollars per share) | $ / shares	$ 10.00
Granted (in dollars per share) | $ / shares	5.86
Forfeited (in dollars per share) | $ / shares	10.50
Exercised (in dollars per share) | $ / shares	3.84
Options outstanding, ending balance (in dollars per share) | $ / shares	$ 8.94