CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 114,585	$ 80,231
Marketable securities	96,631	76,461
Total cash, cash equivalents, and marketable securities	211,216	156,692
Trade accounts receivable, net of allowance of $1,540 and $1,997	154,844	165,641
Deferred income taxes	12,974	12,336
Income taxes receivable	4,502	4,392
Other current assets	9,544	9,148
Total current assets	393,080	348,209
Property and equipment, net	30,156	28,957
Long-term deferred income taxes	69,258	56,745
Long-term other assets	2,783	2,526
Intangible assets, net	45,664	56,574
Goodwill	46,860	43,469
Total assets	587,801	536,480
Current liabilities:
Accounts payable	4,752	3,671
Accrued expenses	42,958	31,624
Accrued compensation and related expenses	47,250	44,401
Deferred revenue	134,672	110,690
Total current liabilities	229,632	190,386
Income taxes payable	24,896	21,269
Long-term deferred revenue	20,859	34,196
Other long-term liabilities	17,709	18,841
Total liabilities	293,096	264,692
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, 1,000 shares authorized; no shares issued and outstanding
Common stock, $0.01 par value, 200,000 shares and 100,000 shares authorized; 76,357 shares and 76,324 shares issued and outstanding	764	764
Additional paid-in capital	141,495	139,565
Retained earnings	153,058	127,826
Accumulated other comprehensive (loss) income:
Net unrealized (loss) gain on available-for-sale marketable securities	(65)	77
Foreign currency translation adjustments	(547)	3,556
Total stockholders' equity	294,705	271,788
Total liabilities and stockholders' equity	$ 587,801	$ 536,480