Discontinued Operations - Income From Discontinued Operations, Net of Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations, net of taxes	$ 2,000	$ 1,157	$ 1,853	$ 2,555
ALG Inc. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	5,221	4,770	13,961	14,050
Cost of revenue (exclusive of depreciation and amortization presented separately below)	1,379	1,409	3,720	4,101
Sales and marketing	304	531	1,243	1,810
Technology and development	373	245	993	827
General and administrative	725	176	1,620	566
Depreciation and amortization	418	1,194	2,910	3,704
Goodwill impairment	0	0	1,923	0
Total costs and operating expenses	3,199	3,555	12,409	11,008
Income from operations	2,022	1,215	1,552	3,042
Interest income	3	261	169	819
Income from discontinued operations before income taxes	2,025	1,476	1,721	3,861
Provision for (benefit from) income taxes	25	319	(132)	1,306
Income from discontinued operations, net of taxes	$ 2,000	$ 1,157	$ 1,853	$ 2,555