Summary of Stock Awards Granted (Detail) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Stock options	7,600	367,167	1,213,376	[1]	1,974,711
Weighted Average Grant Date Fair Value, Stock options	$ 15.61	$ 15.69	$ 11.94		$ 11.34
Restricted Stock Awards (RSAs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Restricted stock awards		110,783	25,775	[2]	116,783
Weighted Average Grant Date Fair Value, Restricted stock awards		$ 13.54	$ 13.71		$ 13.56

[1] Included in 2016 stock option grants are 287,500 options with performance conditions that are not probable of being achieved as of June 30, 2016. When and if deemed probable that certain performance milestones will be achieved within the required time frame, the Company will recognize up to $3.4 million of stock-based compensation related to these grants. The remaining stock options granted during the periods presented in the table have only service-based criteria and vest over four years.

[2] Included in 2016 restricted stock awards (“RSA”) are 18,755 shares granted to certain employees in lieu of a portion of their 2015 annual bonus payments. These RSA grants have six-month vesting schedules. The remaining RSAs will be fully vested by June 2017