Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Operating revenue	$ 204,710	$ 199,370	$ 168,969
Operating expenses:
Costs of services provided	40,471	38,133	33,589
Product development	26,798	24,825	19,208
Sales and marketing	15,848	16,687	13,642
General and administrative	36,480	33,562	26,268
Amortization and depreciation	10,107	9,155	7,514
Total operating expenses	129,704	122,362	100,221
Operating income	75,006	77,008	68,748
Interest income	518	441	557
Interest expense	(1,226)	(1,541)	(759)
Non-operating income (loss) - put options	342	190	647
Non-operating expense - securities litigation	(4,226)	0	0
Foreign exchange gain (loss)	(262)	1,931	4,302
Income before income taxes	70,152	78,029	73,495
Income tax provision	(10,878)	(7,460)	(2,117)
Net income	$ 59,274	$ 70,569	$ 71,378
Basic earnings per common share (in dollars per share)	$ 1.58	$ 1.91	$ 1.89
Diluted earnings per common share (in dollars per share)	$ 1.53	$ 1.80	$ 1.75
Basic weighted average shares outstanding (in shares)	37,588	36,948	37,742
Diluted weighted average shares outstanding (in shares)	38,642	39,100	40,889