Consolidated Balance Sheets - USD ($)	Apr. 02, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 92,428,000	$ 79,641,000
Short-term investments	376,027,000	341,194,000
Accounts receivable, less reserves of $941 and $873 in 2017 and 2016, respectively	58,236,000	55,438,000
Unbilled revenue	1,289,000	2,217,000
Inventories	32,615,000	26,984,000
Prepaid expenses and other current assets	33,349,000	20,870,000
Total current assets	593,944,000	526,344,000
Long-term investments	312,850,000	324,335,000
Property, plant, and equipment, net	57,255,000	53,992,000
Goodwill	95,280,000	95,280,000
Intangible assets, net	7,440,000	8,312,000
Deferred income taxes	27,096,000	28,022,000
Other assets	2,379,000	2,319,000
Total assets	1,096,244,000	1,038,604,000
Current liabilities:
Accounts payable	17,115,000	9,830,000
Accrued expenses	38,904,000	42,539,000
Accrued income taxes	5,696,000	5,193,000
Deferred revenue and customer deposits	13,801,000	8,211,000
Total current liabilities	75,516,000	65,773,000
Reserve for income taxes	5,641,000	5,361,000
Other non-current liabilities	3,875,000	4,871,000
Total liabilities	85,032,000	76,005,000
Shareholders’ equity:
Common stock, $.002 par value – Authorized: 200,000 shares in 2017 and 2016, respectively, issued and outstanding: 86,646 and 85,939 shares in 2017 and 2016, respectively	173,000	172,000
Additional paid-in capital	411,650,000	375,030,000
Retained earnings	652,917,000	643,825,000
Accumulated other comprehensive loss, net of tax	(53,528,000)	(56,428,000)
Total shareholders’ equity	1,011,212,000	962,599,000
Total liabilities and shareholders' equity	$ 1,096,244,000	$ 1,038,604,000

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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Namespace Prefix:	us-gaap_
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.