CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenues	$ 711,764	$ 575,936	$ 440,943
Cost of revenues	188,885	156,979	129,185
Gross margin	522,879	418,957	311,758
Operating expenses:
Selling and marketing	302,226	150,305	98,708
Software development	65,760	55,426	46,757
General and administrative	115,507	103,916	96,956
Purchase amortization	27,931	28,432	15,183
Total operating expenses	511,424	338,079	257,604
Income from operations	11,455	80,878	54,154
Interest and other income	537	516	326
Interest and other expense	(9,411)	(10,481)	(6,943)
Income before income taxes	2,581	70,913	47,537
Income tax expense, net	6,046	26,044	17,803
Net income (loss)	$ (3,465)	$ 44,869	$ 29,734
Net income (loss) per share — basic (in dollars per share)	$ (0.11)	$ 1.48	$ 1.07
Net income (loss) per share — diluted (in dollars per share)	$ (0.11)	$ 1.46	$ 1.05
Weighted average outstanding shares — basic (in shares)	31,950	30,215	27,670
Weighted average outstanding shares — diluted (in shares)	31,950	30,641	28,212