CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 120,864	$ 114,585
Marketable securities	106,068	96,631
Total cash, cash equivalents, and marketable securities	226,932	211,216
Trade accounts receivable, net of allowance of $1,752 and $1,540	135,585	154,844
Deferred income taxes	12,948	12,974
Income taxes receivable	8,429	4,502
Other current assets	12,536	9,544
Total current assets	396,430	393,080
Property and equipment, net	33,855	30,156
Long-term deferred income taxes	70,765	69,258
Long-term other assets	3,016	2,783
Intangible assets, net	39,419	45,664
Goodwill	46,882	46,860
Total assets	590,367	587,801
Current liabilities:
Accounts payable	8,330	4,752
Accrued expenses	40,326	42,958
Accrued compensation and related expenses	37,249	47,250
Deferred revenue	143,001	134,672
Total current liabilities	228,906	229,632
Income taxes payable	24,919	24,896
Long-term deferred revenue	16,214	20,859
Other long-term liabilities	16,751	17,709
Total liabilities	$ 286,790	$ 293,096
Stockholders' equity:
Preferred stock, 1,000 shares authorized; no shares issued and outstanding
Common stock, 200,000 shares authorized; 76,627 shares and 76,357 shares issued and outstanding	$ 766	$ 764
Additional paid-in capital	147,257	141,495
Retained earnings	157,495	153,058
Accumulated other comprehensive loss	(1,941)	(612)
Total stockholders' equity	303,577	294,705
Total liabilities and stockholders' equity	$ 590,367	$ 587,801