Stock Options and Stock-Based Compensation - Schedule of Outstanding Stock Options (Detail) (USD $) | 9 Months Ended | | |
Feb. 28, 2015 | Nov. 30, 2014 | 31-May-14 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | |
Number of Shares, Outstanding Options | 332,500 | 332,500 | 281,666 |
Weighted Average Exercise Price, Outstanding Options | $3.68 | $3.68 | $3.77 |
Weighted Average Remaining Contractual Life (yrs), Outstanding Options | 7 years | | |
Exercisable Options, Number of Shares | 205,002 | | |
Exercisable Options, Weighted Average Exercise Price | $4.24 | | |
Options 1 [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | |
Number of Shares, Outstanding Options | 35,000 | | |
Weighted Average Exercise Price, Outstanding Options | $2.53 | | |
Weighted Average Remaining Contractual Life (yrs), Outstanding Options | 8 years 7 months 6 days | | |
Exercisable Options, Number of Shares | 11,668 | | |
Exercisable Options, Weighted Average Exercise Price | $2.53 | | |
Options 2 [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | |
Number of Shares, Outstanding Options | 112,500 | | |
Weighted Average Exercise Price, Outstanding Options | $2.84 | | |
Weighted Average Remaining Contractual Life (yrs), Outstanding Options | 9 years 3 months 18 days | | |
Exercisable Options, Number of Shares | 8,334 | | |
Exercisable Options, Weighted Average Exercise Price | $2.90 | | |
Options 3 [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | |
Number of Shares, Outstanding Options | 130,000 | | |
Weighted Average Exercise Price, Outstanding Options | $3.65 | | |
Weighted Average Remaining Contractual Life (yrs), Outstanding Options | 6 years 3 months 18 days | | |
Exercisable Options, Number of Shares | 130,000 | | |
Exercisable Options, Weighted Average Exercise Price | $3.65 | | |
Options 4 [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | |
Number of Shares, Outstanding Options | 5,000 | | |
Weighted Average Exercise Price, Outstanding Options | $5.80 | | |
Weighted Average Remaining Contractual Life (yrs), Outstanding Options | 8 months 12 days | | |
Exercisable Options, Number of Shares | 5,000 | | |
Exercisable Options, Weighted Average Exercise Price | $5.80 | | |
Options 5 [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | |
Number of Shares, Outstanding Options | 50,000 | | |
Weighted Average Exercise Price, Outstanding Options | $6.25 | | |
Weighted Average Remaining Contractual Life (yrs), Outstanding Options | 3 years 3 months 18 days | | |
Exercisable Options, Number of Shares | 50,000 | | |
Exercisable Options, Weighted Average Exercise Price | $6.25 | | |