Income Taxes - Summary of Company's Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Capital loss carryforwards	$ 4,648	$ 7,235
Stock compensation expense	4,534	11,307
Other	1,143	1,468
Total deferred tax assets	11,197	21,919
Valuation allowance	(4,648)	(7,235)	$ (7,294)	$ (7,428)
Net deferred tax assets	6,549	14,684
Deferred tax liabilities:
Depreciation and amortization	(1,369)	(1,456)
Capitalized software development costs	(3,479)	(4,923)
Intangible assets	(967)	(1,037)
Deferred tax assets, net	734	7,268
US Country [Member]
Deferred tax assets:
U.S. net operating loss carryforwards	$ 872	$ 1,909