Summary of Stock Awards Granted (Parenthetical) (Detail) - Restricted Stock Units [Member]	3 Months Ended
	Mar. 31, 2017 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock units, granted	161,029	[1]
Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock units, granted	156,029
Maximum [Member] | Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation related to grants | $	$ 5,100,000

[1] The Company granted certain executives 156,029 restricted stock units (“RSU”) with certain sales target and regulatory milestones. As of March 31, 2017, the performance conditions of these RSUs were not probable of being achieved. If and when deemed probable that such performance milestones may be achieved within the required time frame, the Company may recognize up to $5.1 million of stock-based compensation related to these grants. The remaining RSUs are service-based awards granted to the members of the board of directors.