Segment information - Schedule of Segment Information (Details) $ in Thousands	1 Months Ended	3 Months Ended								8 Months Ended	12 Months Ended
	May 01, 2018 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment											2
Revenues:
Total revenue		$ 20,408	$ 21,169	$ 19,386	$ 23,133	$ 14,717	$ 16,054	$ 14,788	$ 14,589		$ 77,486	$ 60,148
Other Income											108	0
Interest Income											617	422
Operating Expenses:
Employee compensation and benefits, excluding equity-based compensation											40,189	31,173
General and administrative expenses, excluding state franchise tax											19,042	12,925
Bad debts											725	1,298
Total											59,956	45,396
Adjusted EBITDA											17,530	14,752
Other income (expense, including state franchise tax)												(157)
Equity based compensation											(1,526)	(27,083)
Interest expense											(2,387)	(4,266)
Depreciation and amortization											(1,931)	(1,464)
Taxes											(1,304)	(449)
Net Income (loss)	$ 621	2,427	$ 2,763	$ 2,817	$ 7,318	605	$ 836	$ (23,875)	$ 3,768	$ 2,960	10,382	(18,667)
Total Assets		64,628				34,798				34,798	64,628	34,798
State franchise tax											135
Corporate Channel
Revenues:
Total revenue											42,836
Franchise Channel
Revenues:
Total revenue											34,650
Operating Segments | Corporate Channel
Revenues:
Total revenue											42,836	34,287
Other Income											0	0
Interest Income											0	0
Operating Expenses:
Employee compensation and benefits, excluding equity-based compensation											23,516	18,662
General and administrative expenses, excluding state franchise tax											8,769	7,200
Bad debts											604	889
Total											32,889	26,751
Adjusted EBITDA											9,947	7,536
Other income (expense, including state franchise tax)												(22)
Equity based compensation											0	0
Interest expense											0	0
Depreciation and amortization											(971)	(945)
Taxes											0	0
Net Income (loss)											8,976	6,569
Total Assets		15,127				6,862				6,862	15,127	6,862
Operating Segments | Franchise Channel
Revenues:
Total revenue											34,650	25,861
Other Income											108	0
Interest Income											617	422
Operating Expenses:
Employee compensation and benefits, excluding equity-based compensation											16,673	12,511
General and administrative expenses, excluding state franchise tax											7,392	4,326
Bad debts											121	409
Total											24,186	17,246
Adjusted EBITDA											10,464	8,615
Other income (expense, including state franchise tax)												0
Equity based compensation											0	0
Interest expense											0	0
Depreciation and amortization											(960)	(519)
Taxes											0	0
Net Income (loss)											9,504	8,096
Total Assets		22,676				8,572				8,572	22,676	8,572
Other
Revenues:
Total revenue											0	0
Other Income											0	0
Interest Income											0	0
Operating Expenses:
Employee compensation and benefits, excluding equity-based compensation											0	0
General and administrative expenses, excluding state franchise tax											2,881	1,399
Bad debts											0	0
Total											2,881	1,399
Adjusted EBITDA											(2,881)	(1,399)
Other income (expense, including state franchise tax)												(135)
Equity based compensation											(1,526)	(27,083)
Interest expense											(2,387)	(4,266)
Depreciation and amortization											0	0
Taxes											(1,304)	(449)
Net Income (loss)											(8,098)	(33,332)
Total Assets		$ 26,825				$ 19,364				$ 19,364	26,825	19,364
Renewal Commissions
Revenues:
Total revenue											22,924	18,357
Renewal Commissions | Corporate Channel
Revenues:
Total revenue											22,924
Renewal Commissions | Franchise Channel
Revenues:
Total revenue											0
Renewal Commissions | Operating Segments | Corporate Channel
Revenues:
Total revenue											22,924	18,357
Renewal Commissions | Operating Segments | Franchise Channel
Revenues:
Total revenue											0	0
Renewal Commissions | Other
Revenues:
Total revenue											0	0
Agency Fees
Revenues:
Total revenue											6,058	5,169
Agency Fees | Corporate Channel
Revenues:
Total revenue											6,058
Agency Fees | Franchise Channel
Revenues:
Total revenue											0
Agency Fees | Operating Segments | Corporate Channel
Revenues:
Total revenue											6,058	5,169
Agency Fees | Operating Segments | Franchise Channel
Revenues:
Total revenue											0	0
Agency Fees | Other
Revenues:
Total revenue											0	0
New Business Commissions
Revenues:
Total revenue											11,961	9,347
New Business Commissions | Corporate Channel
Revenues:
Total revenue											11,961
New Business Commissions | Franchise Channel
Revenues:
Total revenue											0
New Business Commissions | Operating Segments | Corporate Channel
Revenues:
Total revenue											11,961	9,347
New Business Commissions | Operating Segments | Franchise Channel
Revenues:
Total revenue											0	0
New Business Commissions | Other
Revenues:
Total revenue											0	0
Contingent Commissions
Revenues:
Total revenue											5,423	3,831
Contingent Commissions | Corporate Channel
Revenues:
Total revenue											1,893
Contingent Commissions | Franchise Channel
Revenues:
Total revenue											3,530
Contingent Commissions | Operating Segments | Corporate Channel
Revenues:
Total revenue											1,893	1,414
Contingent Commissions | Operating Segments | Franchise Channel
Revenues:
Total revenue											3,530	2,417
Contingent Commissions | Other
Revenues:
Total revenue											0	0
Commissions and agency fees
Revenues:
Total revenue											46,366	36,704
Commissions and agency fees | Operating Segments | Corporate Channel
Revenues:
Total revenue											42,836	34,287
Commissions and agency fees | Operating Segments | Franchise Channel
Revenues:
Total revenue											3,530	2,417
Commissions and agency fees | Other
Revenues:
Total revenue											0	0
Renewal Royalty Fees
Revenues:
Total revenue											19,462	12,104
Renewal Royalty Fees | Corporate Channel
Revenues:
Total revenue											0
Renewal Royalty Fees | Franchise Channel
Revenues:
Total revenue											19,462
Renewal Royalty Fees | Operating Segments | Corporate Channel
Revenues:
Total revenue											0	0
Renewal Royalty Fees | Operating Segments | Franchise Channel
Revenues:
Total revenue											19,462	12,104
Renewal Royalty Fees | Other
Revenues:
Total revenue											0	0
New Business Royalty Fees
Revenues:
Total revenue											7,149	4,873
New Business Royalty Fees | Corporate Channel
Revenues:
Total revenue											0
New Business Royalty Fees | Franchise Channel
Revenues:
Total revenue											7,149
New Business Royalty Fees | Operating Segments | Corporate Channel
Revenues:
Total revenue											0	0
New Business Royalty Fees | Operating Segments | Franchise Channel
Revenues:
Total revenue											7,149	4,873
New Business Royalty Fees | Other
Revenues:
Total revenue											0	0
Initial Franchise Fees
Revenues:
Total revenue											3,784	6,045
Initial Franchise Fees | Operating Segments | Corporate Channel
Revenues:
Total revenue											0	0
Initial Franchise Fees | Operating Segments | Franchise Channel
Revenues:
Total revenue											3,784	6,045
Initial Franchise Fees | Other
Revenues:
Total revenue											0	0
Franchise Revenue
Revenues:
Total revenue											30,503	23,022
Franchise Revenue | Operating Segments | Corporate Channel
Revenues:
Total revenue											0	0
Franchise Revenue | Operating Segments | Franchise Channel
Revenues:
Total revenue											30,503	23,022
Franchise Revenue | Other
Revenues:
Total revenue											0	0
Interest income
Revenues:
Total revenue											617	422
Interest Income											617	422
Interest income | Corporate Channel
Revenues:
Total revenue											0
Interest income | Franchise Channel
Revenues:
Total revenue											617
Interest income | Operating Segments | Corporate Channel
Revenues:
Interest Income											0	0
Interest income | Operating Segments | Franchise Channel
Revenues:
Interest Income											617	422
Interest income | Other
Revenues:
Interest Income											$ 0	$ 0