Business Segments - Financial Performance by Segment and Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Revenue:
Total revenue	$ 32,865	$ 34,038
Segment Operating Expenses:
Consolidated operating expenses	38,242	39,667
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA	(5,377)	(5,629)
Add (deduct)
Interest income (expense), net	(66)	118
Other income (expense), net	10	(7)
Depreciation and amortization	(2,487)	(2,716)
Stock-based compensation	(2,704)	(1,921)
Acquisition, disposition, realignment and contingent payment costs		90
Loss before income taxes	(10,624)	(10,245)
Corporate
Segment Operating Expenses:
Consolidated operating expenses	7,329	7,927
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA, excluding acquisition, disposition and realignment costs	(7,329)	(7,927)
Marketplaces
Segment Revenue:
Total revenue	18,741	20,838
Marketplaces | Operating Segments
Segment Operating Expenses:
Consolidated operating expenses	20,533	22,149
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA, excluding acquisition, disposition and realignment costs	(1,792)	(1,311)
Media
Segment Revenue:
Total revenue	14,124	13,200
Media | Operating Segments
Segment Operating Expenses:
Consolidated operating expenses	10,380	9,591
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA, excluding acquisition, disposition and realignment costs	$ 3,744	$ 3,609