Fair Value of Financial Instruments - Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Liabilities, Fair Value Disclosure [Abstract]
Accruals and other current liabilities	$ 3,583	$ 5,100	$ 2,390
Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Total assets	30,794	70,000	30,355
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	5,143	6,599	4,316
Deferred compensation plan	2,300	2,544	2,275
Cash-settled equity awards	743
Total liabilities	11,551	9,143
Accruals and other current liabilities	3,583	5,100
Deferred compensation plan, current	149	153	115
Fair Value, Recurring \| Money Market Funds
Assets, Fair Value Disclosure [Abstract]
Money market funds	30,794	70,000	30,197
Total assets		70,000
Fair Value, Recurring \| Interest Rate Swap
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap	3,365
Level 1 \| Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Total assets	30,794	70,000	30,197
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	0	0
Deferred compensation plan	2,300	2,544	2,275
Cash-settled equity awards	743
Total liabilities	3,043	2,544
Level 1 \| Fair Value, Recurring \| Money Market Funds
Assets, Fair Value Disclosure [Abstract]
Money market funds	30,794	70,000	30,197
Total assets		70,000
Level 1 \| Fair Value, Recurring \| Interest Rate Swap
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap	0
Level 2 \| Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Total assets	0	0	158
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	0	0
Deferred compensation plan	0	0
Cash-settled equity awards	0
Total liabilities	3,365	0
Level 2 \| Fair Value, Recurring \| Money Market Funds
Assets, Fair Value Disclosure [Abstract]
Money market funds	0	0
Level 2 \| Fair Value, Recurring \| Interest Rate Swap
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap	3,365
Level 3 \| Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Total assets	0	0
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	5,143	6,599	$ 4,316
Deferred compensation plan	0	0
Cash-settled equity awards	0
Total liabilities	5,143	6,599
Level 3 \| Fair Value, Recurring \| Money Market Funds
Assets, Fair Value Disclosure [Abstract]
Money market funds	0	$ 0
Level 3 \| Fair Value, Recurring \| Interest Rate Swap
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swap	$ 0

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Deferred Compensation Liability, Fair Value Disclosure

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value of financial and nonfinancial obligations.

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