CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 70,594	$ 93,026
Marketable securities	63,167	126,052
Total cash, cash equivalents, and marketable securities	133,761	219,078
Trade accounts receivable, net of allowance of $4,126 and $4,631	265,028	211,846
Income taxes receivable	14,155	4,770
Other current assets	12,188	10,791
Total current assets	425,132	446,485
Property and equipment, net	38,281	31,319
Deferred income taxes	69,898	65,730
Long-term other assets	3,990	4,030
Intangible assets, net	44,191	33,418
Goodwill	73,164	46,776
Total assets	654,656	627,758
Current liabilities:
Accounts payable	14,414	12,675
Accrued expenses	36,751	42,768
Accrued compensation and related expenses	60,660	55,872
Deferred revenue	175,647	155,873
Total current liabilities	287,472	267,188
Income taxes payable	4,263	5,618
Long-term deferred revenue	10,989	15,805
Other long-term liabilities	16,043	16,288
Total liabilities	318,767	304,899
Commitments and contingencies (Note 12)
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 authorized; 76,591 shares and 76,488 shares issued and outstanding	766	765
Additional paid-in capital	143,903	145,418
Retained earnings	198,315	180,183
Accumulated other comprehensive loss:
Net unrealized loss on available-for-sale marketable securities, net of tax	(169)	(150)
Foreign currency translation adjustments	(6,926)	(3,357)
Total stockholders' equity	335,889	322,859
Total liabilities and stockholders' equity	$ 654,656	$ 627,758

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Balance Type:	credit
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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.