CONSOLIDATED BALANCE SHEETS - USD ($)		Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents		$ 108,212,000	$ 106,582,000
Short-term investments		427,348,000	297,961,000
Accounts receivable, less reserves of $1,646 and $1,568 in 2018 and 2017, respectively		119,172,000	119,388,000
Unbilled revenue		8,312,000	7,454,000
Inventories		83,282,000	67,923,000
Prepaid expenses and other current assets		34,000,000	30,683,000
Total current assets		780,326,000	629,991,000
Long-term investments		262,039,000	423,441,000
Property, plant, and equipment, net		91,396,000	78,048,000
Goodwill		113,208,000	113,208,000
Intangible assets, net		10,113,000	13,189,000
Deferred income taxes		28,660,000	27,385,000
Other assets		3,925,000	2,491,000
Total assets		1,289,667,000	1,287,753,000
Current liabilities:
Accounts payable		16,230,000	23,463,000
Accrued expenses		60,220,000	68,249,000
Accrued income taxes		5,062,000	11,503,000
Deferred revenue and customer deposits		9,845,000	9,420,000
Total current liabilities		91,357,000	112,635,000
Deferred income taxes		962,000	312,000
Reserve for income taxes		7,106,000	6,488,000
Accrued income taxes		51,113,000	66,741,000
Other non-current liabilities		3,866,000	5,904,000
Total liabilities		154,404,000	192,080,000
Commitments and contingencies (Note 10)
Shareholders’ equity:
Common stock, $.002 par value – Authorized: 300,000 and 200,000 shares in 2018 and 2017, respectively, issued and outstanding: 170,820 and 173,507 shares in 2018 and 2017, respectively	[1]	342,000	347,000
Additional paid-in capital	[1]	529,208,000	461,338,000
Retained earnings	[1]	646,214,000	668,587,000
Accumulated other comprehensive loss, net of tax	[1]	(40,501,000)	(34,599,000)
Total shareholders’ equity	[1]	1,135,263,000	1,095,673,000
Total liabilities and shareholders' equity		$ 1,289,667,000	$ 1,287,753,000

[1] Prior period amounts have been adjusted to reflect the two-for-one stock split effected in the form of a stock dividend