Investments (Details) - USD ($)				6 Months Ended	12 Months Ended
	Jul. 17, 2015	Jul. 02, 2015	Jan. 16, 2014	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Investments					$ 1,442,000	$ 2,685,000
Payment to acquire investments			$ 4,000,000
(Loss) gain in equity interests					$ (1,243,000)	$ (328,000)	$ 520,000
A Vendor Services Company
Schedule of Equity Method Investments [Line Items]
Approximate % Ownership	21.10%				34.10%	34.10%
Payment to acquire investments	$ 1,000,000
Catchafire, Inc.
Schedule of Equity Method Investments [Line Items]
Approximate % Ownership					3.60%
Cost method investments					$ 400,000
Jetaport, Inc.
Schedule of Equity Method Investments [Line Items]
Approximate % Ownership		17.60%
Payment to acquire investments		$ 1,500,000
Other than temporary impairment				$ 1,032,000
Carrying value of investment				$ 0
Touch Media International Holdings
Schedule of Equity Method Investments [Line Items]
Approximate % Ownership			3.00%
Other than temporary impairment							4,000,000
Carrying value of investment							$ 0