Debt Obligations - Future Payments (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Future principal payments of long-term debt
2022	$ 23,000
2023	34,000
2023	26,500
2024	152,500
Total debt	236,000
Interest expense
Interest expense on notes to former owners	1,354	$ 1,531	$ 642
Interest expense on borrowings and unused commitment fees	5,319	6,887	2,211
Interest expense on interest rate swaps	338
Letter of credit fees	830	512	474
Amortization of debt financing costs	544	387	383
Total	$ 8,385	$ 9,317	$ 3,710

Amount of interest expense on interest rate swaps.

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Represents the amount of fees associated with the letter of credit.

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Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

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- Definition

Amount of short-term and long-term debt and lease obligation.

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

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount of interest expense incurred on a debt or other obligation to related party.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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