Business Segments - Financial Performance by Segment and Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Segment Revenue:
Total revenue	$ 154,956	$ 155,042
Segment Operating Expenses:
Consolidated operating expenses	162,433	156,843
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA	(7,477)	(1,481)
Add (deduct)
Interest income (expense), net	225	305
Other income (expense), net	40	(78)
Depreciation and amortization	(10,111)	(10,270)
Stock-based compensation	(9,364)	(9,431)
Acquisition, disposition, realignment and contingent payment costs	(90)	(2,140)
Loss before income taxes	(26,777)	(23,095)
Corporate
Segment Operating Expenses:
Consolidated operating expenses	30,025	27,089
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA	(30,025)	(27,089)
Acquisition, disposition and realignment costs
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA		320
Marketplaces
Segment Revenue:
Total revenue	89,625	93,937
Marketplaces | Operating Segments
Segment Operating Expenses:
Consolidated operating expenses	91,807	95,068
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA	(2,182)	(1,131)
Media
Segment Revenue:
Total revenue	65,331	61,105
Media | Operating Segments
Segment Operating Expenses:
Consolidated operating expenses	40,601	34,686
Segment operating contribution and Reconciliation to consolidated pre-tax income (loss):
Adjusted EBITDA	$ 24,730	$ 26,419