Other Current Liabilities - Summary of Other Current Liabilities (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Accrued payroll expenses	$ 7,120,055	$ 7,032,508
Deferred revenue	1,868,223	1,893,508
Dividends payable	1,367,761	1,286,381
Trade sales payable	1,250,454	1,276,170
Deferred rent	1,561,486	1,349,515
Other accrued expenses	6,013,129	5,961,113
Other current liabilities	$ 19,181,108	$ 18,799,195

Trade sales payable.

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Carrying value as of the balance sheet date of the obligations incurred through that date and payable for employees' services provided. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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For a classified balance sheet, the cumulative difference as of the balance sheet date between the payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense, by the lessor or lessee, respectively, within one year of the balance sheet date.

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The carrying amount of consideration received or receivable as of the balance sheet date on potential earnings that were not recognized as revenue in conformity with GAAP, and which are expected to be recognized as such within one year or the normal operating cycle, if longer, including sales, license fees, and royalties, but excluding interest income.

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Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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Amount of liabilities classified as other, due within one year or the normal operating cycle, if longer.

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