CONSOLIDATED STATEMENTS OF OPERATIONS (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]
Revenues	$ 440,943	$ 349,936	$ 251,738
Cost of revenues	129,185	114,866	88,167
Gross margin	311,758	235,070	163,571
Operating expenses:
Selling and marketing	98,708	84,113	61,164
Software development	46,757	32,756	20,037
General and administrative	96,956	77,154	58,362
Purchase amortization	15,183	13,607	2,237
Total operating expenses	257,604	207,630	141,800
Income from operations	54,154	27,440	21,771
Interest and other income	326	526	798
Interest and other expense	(6,943)	(4,832)	0
Income before income taxes	47,537	23,134	22,569
Income tax expense, net	17,803	13,219	7,913
Net income	$ 29,734	$ 9,915	$ 14,656
Net income per share — basic (in dollars per share)	$ 1.07	$ 0.37	$ 0.63
Net income per share — diluted (in dollars per share)	$ 1.05	$ 0.37	$ 0.62
Weighted average outstanding shares — basic (in shares)	27,670	26,533	23,131
Weighted average outstanding shares — diluted (in shares)	28,212	26,949	23,527