Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Operating revenue	$ 64,712	$ 51,476	$ 128,465	$ 102,880
Operating expenses:
Cost of services provided	18,699	9,964	38,184	19,576
Product development	7,288	6,758	14,335	13,451
Sales and marketing	3,611	3,784	6,990	7,085
General and administrative	12,121	11,068	22,867	20,909
Amortization and depreciation	2,570	2,441	5,167	4,993
Total operating expenses	44,289	34,015	87,543	66,014
Operating income	20,423	17,461	40,922	36,866
Interest income	44	130	105	265
Interest expense	(625)	(211)	(1,344)	(458)
Non-operating (loss)/income - put options	0	(139)	0	315
Foreign currency exchange gain (loss)	330	(336)	1,222	(455)
Income before income taxes	20,172	16,905	40,905	36,533
Income tax expense	(1,136)	(3,326)	(3,533)	(7,537)
Net income	$ 19,036	$ 13,579	$ 37,372	$ 28,996
Basic earnings per common share	$ 0.54	$ 0.35	$ 1.06	$ 0.76
Diluted earnings per common share	$ 0.54	$ 0.35	$ 1.05	$ 0.75
Basic weighted average shares outstanding	35,046	38,427	35,375	38,373
Diluted weighted average shares outstanding	35,269	38,647	35,610	38,624