Business Combinations - Summary of Preliminary Values Allocated to Identifiable Intangible Assets and Estimated Useful Lives (Details) - USD ($)						9 Months Ended
	Jul. 23, 2020	Feb. 10, 2020	Oct. 14, 2019	Aug. 13, 2019	Jul. 11, 2019	Sep. 30, 2020
Hawk Parent Holdings LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value					$ 301,000,000
Hawk Parent Holdings LLC | Trade Names
Business Acquisition [Line Items]
Identifiable intangible assets, fair value					20,000,000.0
Identifiable intangible assets, useful life, description						Indefinite
TriSource Solutions, LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value				$ 30,500,000
TriSource Solutions, LLC | Trade Names
Business Acquisition [Line Items]
Identifiable intangible assets, fair value				700,000
Identifiable intangible assets, useful life, description						Indefinite
APS Payments
Business Acquisition [Line Items]
Identifiable intangible assets, fair value			$ 21,500,000
APS Payments | Trade Names
Business Acquisition [Line Items]
Identifiable intangible assets, fair value			500,000
Identifiable intangible assets, useful life, description						Indefinite
Ventanex
Business Acquisition [Line Items]
Identifiable intangible assets, fair value		$ 26,890,000
Ventanex | Trade Names
Business Acquisition [Line Items]
Identifiable intangible assets, fair value		400,000
Identifiable intangible assets, useful life, description						Indefinite
cPayPlus
Business Acquisition [Line Items]
Identifiable intangible assets, fair value	$ 7,720,000
cPayPlus | Trade Names
Business Acquisition [Line Items]
Identifiable intangible assets, fair value	100,000
Identifiable intangible assets, useful life, description						Indefinite
Non-Complete Agreements | Hawk Parent Holdings LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value					$ 3,000,000.0
Identifiable intangible assets, useful life					2 years
Non-Complete Agreements | TriSource Solutions, LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value				$ 400,000
Identifiable intangible assets, useful life				5 years
Non-Complete Agreements | APS Payments
Business Acquisition [Line Items]
Identifiable intangible assets, fair value			$ 500,000
Identifiable intangible assets, useful life			5 years
Non-Complete Agreements | Ventanex
Business Acquisition [Line Items]
Identifiable intangible assets, fair value		$ 100,000
Identifiable intangible assets, useful life		5 years
Non-Complete Agreements | cPayPlus
Business Acquisition [Line Items]
Identifiable intangible assets, fair value	$ 100,000
Identifiable intangible assets, useful life	5 years
Developed Technology | Hawk Parent Holdings LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value					$ 65,000,000.0
Identifiable intangible assets, useful life					10 years
Developed Technology | TriSource Solutions, LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value				$ 3,900,000
Identifiable intangible assets, useful life				3 years
Developed Technology | Ventanex
Business Acquisition [Line Items]
Identifiable intangible assets, fair value		$ 4,100,000
Identifiable intangible assets, useful life		3 years
Developed Technology | cPayPlus
Business Acquisition [Line Items]
Identifiable intangible assets, fair value	$ 6,700,000
Identifiable intangible assets, useful life	3 years
Merchant Relationships | Hawk Parent Holdings LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value					$ 210,000,000.0
Identifiable intangible assets, useful life					3 years
Merchant Relationships | TriSource Solutions, LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value				$ 25,500,000
Identifiable intangible assets, useful life				10 years
Merchant Relationships | APS Payments
Business Acquisition [Line Items]
Identifiable intangible assets, fair value			$ 20,500,000
Identifiable intangible assets, useful life			9 years
Merchant Relationships | Ventanex
Business Acquisition [Line Items]
Identifiable intangible assets, fair value		$ 22,300,000
Identifiable intangible assets, useful life		10 years
Merchant Relationships | cPayPlus
Business Acquisition [Line Items]
Identifiable intangible assets, fair value	$ 900,000
Identifiable intangible assets, useful life	10 years
Channel Relationships | Hawk Parent Holdings LLC
Business Acquisition [Line Items]
Identifiable intangible assets, fair value					$ 3,000,000.0
Identifiable intangible assets, useful life					10 years