Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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-Section 50
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- Definition

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

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Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock.

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Fair Value of Financial Instruments - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Amounts owed to employees participating in the deferred compensation plan	$ 2,800,000	$ 3,200,000
Contingent consideration liability	0
Change in fair value of contingent consideration	3,340,000	0	$ 450,000
AccSys LLC (Restaurant Magic)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration liability	0	3,300,000
Change in fair value of contingent consideration	3,300,000
Fair Value, Inputs, Level 2 \| Convertible Debt \| Convertible Senior Notes Due 2024
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of notes	30,600,000	$ 102,300,000
Fair Value, Inputs, Level 2 \| Convertible Debt \| Convertible Senior Notes Due 2026
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of notes	$ 195,400,000