Goodwill and Intangible Assets - Summary of Activity in Carrying Value of Goodwill by Reporting Unit (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Goodwill [Line Items]
Beginning Balance	$ 158,817,000	$ 78,172,000
Acquisition	42,886,000	81,134,000
Goodwill impairment charge	(201,703,000)	0
Ending Balance	0	159,306,000
Ecommerce
Goodwill [Line Items]
Beginning Balance	152,876,000	72,231,000
Acquisition	42,886,000	81,134,000
Goodwill impairment charge	(195,762,000)
Ending Balance	0	153,365,000
Wholesale
Goodwill [Line Items]
Beginning Balance	1,720,000	1,720,000
Acquisition	0	0
Goodwill impairment charge	(1,720,000)
Ending Balance	0	1,720,000
TDA
Goodwill [Line Items]
Beginning Balance	4,221,000	4,221,000
Acquisition	0	0
Goodwill impairment charge	(4,221,000)
Ending Balance	$ 0	$ 4,221,000