Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Revenues	$ 37,256	$ 35,447	$ 120,759	$ 114,140
Cost of revenues	4,322	3,989	12,733	11,672
Gross profit	32,934	31,458	108,026	102,468
Operating expenses:
Sales and marketing	18,449	17,427	57,563	49,753
General and administrative	10,510	9,836	30,659	28,583
Unexchanged promotional shares	22,000	0	22,000	3,000
Total operating expenses	50,959	27,263	110,222	81,336
Income (loss) from operations	(18,025)	4,195	(2,196)	21,132
Other income	224	135	369	218
Income (loss) before income taxes	(17,801)	4,330	(1,827)	21,350
Income taxes	1,235	896	6,414	6,908
Net income (loss)	$ (19,036)	$ 3,434	$ (8,241)	$ 14,442
Basic net income (loss) per share (in dollars per share)	$ (1.24)	$ 0.22	$ (0.54)	$ 0.91
Diluted net income (loss) per share (in dollars per share)	$ (1.24)	$ 0.22	$ (0.54)	$ 0.90
Shares used in computing basic net income (loss) per share (in shares)	15,362	15,884	15,362	15,935
Shares used in computing diluted net income (loss) per share (in shares)	15,362	15,922	15,362	16,041