Stock-Based Compensation - Additional Information (Detail) - shares	9 Months Ended
	Sep. 30, 2015	May. 31, 2014	May. 31, 2013
Nonqualified Incentive Stock Option Plan [Member] | Stock Option [ Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares to be issued under incentive stock option plan			3,000,000
Shares for future grants	29,485
Stock option plan termination date	Dec. 31, 2019
Option exercisable rate	25.00%
Option exercisable period	4 years
Options expire period	15 years
Vesting period in years, start	4 years
Share based compensation options exercisable period	2022
Options vest and exercisable Description	The options are exercisable beginning four years from the date of grant at the rate of 25% per year for four years. Options expire at the end of fifteen years from the date of grant
Vesting period in years	7 years
Nonqualified Incentive Stock Option Plan [Member] | Stock Option [ Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock price percentage to fair value at grant date	100.00%
Non-Employee Directors Stock Option Plan [ Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares to be issued under incentive stock option plan		230,000
Shares for future grants	20,000
Option exercisable rate	25.00%
Option exercisable period	1 year
Options expire period	15 years
Share based compensation options exercisable period	2018
Options vest and exercisable Description	The options are exercisable beginning one year from the date of grant at the rate of 25% per year for four years
Vesting period in years	4 years
Number of options granted for non-employee director	10,000
Non-Employee Directors Stock Option Plan [ Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock price percentage to fair value at grant date	100.00%