Amount of amortization expense attributable to debt issuance costs.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Represents the charge against earnings during the period for commitment fees and debt issuance expenses.

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Date the credit facility terminates, in CCYY-MM-DD format.

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Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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Long-Term Debt and Line-of-Credit - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Debt Instrument [Line Items]
Remaining principal balance amount paid				$ 1,200,000	$ 400,000
Debt issuance costs		$ 31,300	$ 6,200	$ 37,600	$ 12,500
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, frequency of commitment fee payment				quarterly
Unused commitment fee percentage				0.50%
JPMorgan Chase Bank, N. A. \| Credit Agreement \| Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility amount	$ 4,000,000	$ 4,000,000		$ 4,000,000
Credit facility, terminate date				Jun. 30, 2019
JPMorgan Chase Bank, N. A. \| Credit Agreement \| LIBO Rate \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, variable interest rate				2.50%
JPMorgan Chase Bank, N. A. \| Credit Agreement \| Floor Rate \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, variable interest rate				2.50%
JPMorgan Chase Bank, N. A. \| Term Loan \| Credit Agreement
Debt Instrument [Line Items]
Remaining principal balance amount paid	1,000,000
Prepayment costs	$ 0
Unamortized debt issuance costs				$ 25,100