Business Segments - Financial Performance by Segment and Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Revenue:
Total revenue	$ 50,968	$ 35,789	$ 83,833	$ 69,827
Segment Operating Expenses:
Consolidated operating expenses	48,866	37,725	87,108	77,392
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA	2,102	(1,936)	(3,275)	(7,565)
Add (deduct)
Interest income (expense), net	(97)	60	(163)	178
Other income, net	3,837	19	3,847	12
Depreciation and amortization	(2,506)	(2,662)	(4,993)	(5,378)
Stock-based compensation	(2,523)	(2,209)	(5,227)	(4,130)
Acquisition, disposition, realignment and contingent payment costs				90
Income (loss) before income taxes	813	(6,728)	(9,811)	(16,973)
Temporary cuts in salaries and compensation	1,500
Strategic shared services and corporate overhead
Segment Operating Expenses:
Consolidated operating expenses	6,330	7,237	13,659	15,164
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA, excluding acquisition, disposition and realignment costs	(6,330)	(7,237)	(13,659)	(15,164)
Add (deduct)
Strategic shared services	1,800	2,000	3,900	4,100
Overhead costs	4,500	5,200	9,800	11,100
Product
Segment Revenue:
Total revenue	35,922	15,869	52,304	33,410
Service
Segment Revenue:
Total revenue	15,046	19,920	31,529	36,417
Marketplaces
Segment Revenue:
Total revenue	38,647	19,189	57,388	40,027
Marketplaces | Operating Segments
Segment Operating Expenses:
Consolidated operating expenses	34,990	20,533	55,523	42,682
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA, excluding acquisition, disposition and realignment costs	3,657	(1,344)	1,865	(2,655)
Marketplaces | Product and Service, Society6 Group
Segment Revenue:
Total revenue	34,665	15,203	50,658	32,201
Marketplaces | Product and Service, Saatchi Art Group
Segment Revenue:
Total revenue	3,982	3,986	6,730	7,826
Marketplaces | Product
Segment Revenue:
Total revenue	35,922	15,869	52,303	33,410
Marketplaces | Product, Society6 Group
Segment Revenue:
Total revenue	34,582	15,181	50,352	32,179
Marketplaces | Product, Saatchi Art Group
Segment Revenue:
Total revenue	1,340	688	1,951	1,231
Marketplaces | Service
Segment Revenue:
Total revenue	2,725	3,320	5,085	6,617
Marketplaces | Service, Society6 Group
Segment Revenue:
Total revenue	83	22	306	22
Marketplaces | Service, Saatchi Art Group
Segment Revenue:
Total revenue	2,642	3,298	4,779	6,595
Media
Segment Revenue:
Total revenue	12,321	16,600	26,445	29,800
Media | Operating Segments
Segment Operating Expenses:
Consolidated operating expenses	7,546	9,955	17,926	19,546
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA, excluding acquisition, disposition and realignment costs	4,775	6,645	8,519	10,254
Media | Product
Segment Revenue:
Total revenue			1
Media | Service
Segment Revenue:
Total revenue	$ 12,321	$ 16,600	$ 26,444	$ 29,800