Schedule I - Valuation and Qualifying Accounts (Detail) - USD ($) |
12 Months Ended | |
---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Allowance for Doubtful Accounts (Deducted from Accounts Receivable) [Member] | ||
Valuation and Qualifying Accounts Disclosure [Line Items] | ||
Balance at Beginning of Period | $ 1,537,353 | $ 596,380 |
Charged to Costs and Expenses | 1,471,875 | 2,061,553 |
Deductions | 1,385,820 | 1,120,580 |
Balance at End of Period | 1,623,408 | 1,537,353 |
Valuation Allowance for Deferred Tax Assets [Member] | ||
Valuation and Qualifying Accounts Disclosure [Line Items] | ||
Balance at Beginning of Period | 528,179 | 594,079 |
Charged to Costs and Expenses | 36,794 | 69,867 |
Deductions | 236,803 | 135,767 |
Balance at End of Period | $ 328,170 | $ 528,179 |