Business Combinations - Additional Information (Details)								2 Months Ended	3 Months Ended		6 Months Ended			8 Months Ended	9 Months Ended
	Jul. 23, 2020 USD ($)	Apr. 06, 2020 USD ($)	Feb. 10, 2020 USD ($)	Oct. 14, 2019 USD ($) EarnoutPayment	Aug. 13, 2019 USD ($)	Jul. 11, 2019 USD ($)	Jul. 10, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jul. 10, 2019 USD ($)	Jun. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Goodwill								$ 415,510,625	$ 415,510,625	$ 370,779,661				$ 415,510,625	$ 415,510,625	$ 389,660,519	$ 119,529,202
Revenue							$ 2,333,837		37,634,537	23,926,474		$ 47,042,917			113,597,599
Net income (loss)							$ (32,763,009)		(9,503,222)	$ (8,480,761)	$ (16,059,684)	$ (23,742,530)	$ 9,020,479		$ (25,562,906)
Hawk Parent Holdings LLC
Business Acquisition [Line Items]
Merger agreement, description															The amount of cash consideration paid to selling Hawk Parent members at the Closing was equal to the following: (i) the total cash and cash equivalents of Thunder Bridge (including funds in its trust account after the redemption of its public stockholders and the proceeds of any debt or equity financing), minus (ii) the amount of Thunder Bridge’s unpaid expenses and obligations, plus (iii) the cash and cash equivalents of Hawk Parent as of immediately prior to the effective time of the Business Combination (excluding restricted cash), minus (iv) the amount of unpaid transaction expenses of Hawk Parent as of the Closing, minus (v) the amount of the indebtedness and other debt-like items of Hawk Parent and its subsidiaries as of the Closing, minus (vi) the amount of change of control and similar payments payable to employees of Hawk Parent in connection with the Business Combination, minus (vii) an amount of cash reserves equal to $10,000,000, minus (viii) a cash escrow of $150,000, minus (ix) an amount equal to $2,000,000 to be held by a representative of the selling Hawk Parent members, minus (x) the cash payment required in connection with the related warrant amendment, minus (xi) an amount required to be deposited on the balance sheet of Hawk Parent in connection with the Business Combination.
Amount of equal cash reserve for merger consideration						$ 10,000,000
Cash escrow						150,000
Amount to be held by representative for merger consideration						2,000,000
Goodwill						339,911,400
Cash Consideration						$ 260,811,062
TriSource Solutions, LLC
Business Acquisition [Line Items]
Goodwill					$ 30,868,261
Cash Consideration					60,235,090
Revenue									8,300,000						$ 23,100,000
Net income (loss)									1,700,000						4,000,000.0
TriSource Solutions, LLC | Maximum
Business Acquisition [Line Items]
Contingent earn-out right to be received					$ 5,000,000.0
APS Payments
Business Acquisition [Line Items]
Goodwill				$ 25,926,861
Cash Consideration				30,465,454
Earnout payment		$ 14,300,000		$ 30,000,000.0
Number of cash earn-out payments | EarnoutPayment				3
Revenue									3,300,000						10,400,000
Net income (loss)									(600,000)						300,000
Ventanex
Business Acquisition [Line Items]
Goodwill			$ 12,200,461
Cash Consideration			35,939,129
Revenue									3,200,000					7,600,000
Net income (loss)									500,000					$ 500,000
Ventanex | Maximum
Business Acquisition [Line Items]
Contingent earn-out right to be received			$ 14,000,000
cPayPlus
Business Acquisition [Line Items]
Goodwill	$ 6,603,642
Cash Consideration	7,846,959
Revenue								400,000
Net income (loss)								$ 0.0
cPayPlus | Maximum
Business Acquisition [Line Items]
Contingent earn-out right to be received	$ 8,000,000
APS, Vantanex and cPayPlus Acquisitions
Business Acquisition [Line Items]
Transactions costs									$ 1,400,000						$ 3,500,000