Income Taxes - NOLs (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net operating loss carry-forwards
Interest expense recognized for uncertain tax positions	$ 0	$ 0	$ 0
Penalties recognized for uncertain tax positions	0	$ 0	$ 0
U.S. federal
Net operating loss carry-forwards
Net operating loss carry-forwards	100,840,000
Net operating loss carry-forwards available to offset future taxable income annually under Section 382	7,550,000
U.S. federal | Transpera, Inc.
Net operating loss carry-forwards
Net operating loss carry-forwards available to offset future taxable income annually under Section 382	161,000
U.S. federal | ScanScout
Net operating loss carry-forwards
Net operating loss carry-forwards available to offset future taxable income annually under Section 382	2,060,000
State
Net operating loss carry-forwards
Net operating loss carry-forwards	56,876,000
Foreign | United Kingdom
Net operating loss carry-forwards
Net operating loss carry-forwards	7,590,000
Foreign | Germany
Net operating loss carry-forwards
Net operating loss carry-forwards	6,787,000
Foreign | Brazil
Net operating loss carry-forwards
Net operating loss carry-forwards	158,000
U.S. federal and state
Net operating loss carry-forwards
Net operating loss carry-forwards from excess tax deductions attributable to equity compensation	$ 3,885,000