Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 108,827	$ 77,525
Marketable securities	79,618	45,460
Total cash, cash equivalents, and marketable securities	188,445	122,985
Trade accounts receivable, net of allowance of $772 and $963	90,583	134,066
Deferred income taxes	10,152	10,202
Income taxes receivable	4,199	6,261
Other current assets	6,929	5,496
Total current assets	300,308	279,010
Property and equipment, net	28,977	30,827
Long-term deferred income taxes	49,693	49,292
Long-term other assets	1,657	1,680
Intangible assets, net	49,910	58,232
Goodwill	20,451	20,451
Total assets	450,996	439,492
Current liabilities:
Accounts payable	2,347	3,330
Accrued expenses	20,741	15,534
Accrued compensation and related expenses	31,925	40,715
Deferred revenue	91,758	95,546
Total current liabilities	146,771	155,125
Income taxes payable	13,748	13,551
Long-term deferred revenue	17,954	18,719
Other long-term liabilities	17,466	15,618
Total liabilities	195,939	203,013
Stockholders' equity:
Preferred stock, 1,000 shares authorized; no shares issued and outstanding
Common stock, 100,000 shares authorized; 37,989 shares and 37,945 shares issued and outstanding	380	379
Additional paid-in capital	138,271	138,576
Retained earnings	113,410	94,349
Accumulated other comprehensive income	2,996	3,175
Total stockholders' equity	255,057	236,479
Total liabilities and stockholders' equity	$ 450,996	$ 439,492