Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 144,330	$ 80,231
Marketable securities	76,634	76,461
Total cash, cash equivalents, and marketable securities	220,964	156,692
Trade accounts receivable, net of allowance of $1,762 and $1,997	108,651	165,628
Deferred income taxes	11,132	11,106
Income taxes receivable	4,795	4,708
Other current assets	8,537	9,148
Total current assets	354,079	347,282
Property and equipment, net	27,838	28,957
Long-term deferred income taxes	60,938	60,925
Long-term other assets	3,169	2,526
Intangible assets, net	52,818	56,574
Goodwill	36,869	36,869
Total assets	535,711	533,133
Current liabilities:
Accounts payable	4,799	3,678
Accrued expenses	23,461	27,957
Accrued compensation and related expenses	25,682	44,399
Deferred revenue	134,077	110,882
Total current liabilities	188,019	186,916
Income taxes payable	21,431	21,392
Long-term deferred revenue	29,396	34,196
Other long-term liabilities	18,024	18,841
Total liabilities	256,870	261,345
Stockholders' equity:
Preferred stock, 1,000 shares authorized; no shares issued and outstanding
Common stock, 100,000 shares authorized; 76,305 shares and 76,324 shares issued and outstanding	763	764
Additional paid-in capital	137,583	139,565
Retained earnings	136,446	127,826
Accumulated other comprehensive income	4,049	3,633
Total stockholders' equity	278,841	271,788
Total liabilities and stockholders' equity	$ 535,711	$ 533,133