Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 107,371	$ 106,582
Short-term investments	420,016	297,961
Accounts receivable, less reserves of $1,508 and $1,568 in 2018 and 2017, respectively	135,441	119,388
Unbilled revenue	13,948	7,454
Inventories	94,035	67,923
Prepaid expenses and other current assets	27,687	30,683
Total current assets	798,498	629,991
Long-term investments	281,929	423,441
Property, plant, and equipment, net	88,930	78,048
Goodwill	113,208	113,208
Intangible assets, net	10,882	13,189
Deferred income taxes	27,376	27,385
Other assets	3,873	2,491
Total assets	1,324,696	1,287,753
Current liabilities:
Accounts payable	22,295	23,463
Accrued expenses	66,632	68,249
Accrued income taxes	8,974	11,503
Deferred revenue and customer deposits	13,252	9,420
Total current liabilities	111,153	112,635
Deferred income taxes	372	312
Reserve for income taxes	6,646	6,488
Accrued income taxes	51,607	66,741
Other non-current liabilities	5,474	5,904
Total liabilities	175,252	192,080
Shareholders’ equity:
Common stock, $.002 par value – Authorized: 300,000 and 200,000 shares in 2018 and 2017, respectively, issued and outstanding: 172,191 and 173,507 shares in 2018 and 2017, respectively	345	347
Additional paid-in capital	518,556	461,338
Retained earnings	670,935	668,587
Accumulated other comprehensive loss, net of tax	(40,392)	(34,599)
Total shareholders’ equity	1,149,444	1,095,673
Total liabilities and shareholders' equity	$ 1,324,696	$ 1,287,753

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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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.