Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 59,193	$ 53,262	[1]
Short-term investments	47,429	51,740	[1]
Accounts receivable, net	42,190	41,922	[1]
Inventories:
Raw materials and purchased parts	45,436	47,186	[1]
Work in process	12,257	15,504	[1]
Finished goods	15,273	19,999	[1]
Total inventories	72,966	82,689	[1]
Deferred income taxes	6,049	6,646	[1]
Other current assets	6,924	7,557	[1]
Total current assets	234,751	243,816	[1]
Property, plant and equipment, at cost:
Land and land improvements	11,891	12,002	[1]
Buildings and building improvements	31,416	31,190	[1]
Machinery and equipment	39,042	38,007	[1]
Property plant and equipment, gross	82,349	81,199	[1]
Less accumulated depreciation and amortization	(46,792)	(44,218)	[1]
Net property, plant and equipment	35,557	36,981	[1]
Goodwill	57,106	58,060	[1]
Intangible assets, net	19,278	21,828	[1]
Other assets	1,263	923	[1]
Total consolidated assets	347,955	361,608	[1]
Current liabilities:
Accounts payable	15,185	18,625	[1]
Accrued compensation and benefits	10,082	12,652	[1]
Accrued warranty	6,134	6,801	[1]
Deferred profit	4,159	2,821	[1]
Income taxes payable	3,266	2,518	[1]
Other accrued liabilities	7,606	8,454	[1]
Total current liabilities	46,432	51,871	[1]
Other accrued liabilities	5,951	5,964	[1]
Deferred income taxes	11,913	12,742	[1]
Commitments and contingencies			[1]
Stockholders' equity:
Preferred stock, $1 par value; 1,000 shares authorized, none issued			[1]
Common stock, $1 par value; 60,000 shares authorized, 24,473 shares issued and outstanding in 2012 and 24,330 shares in 2011	24,473	24,330	[1]
Paid-in capital	80,743	77,658	[1]
Retained earnings	180,792	189,055	[1]
Accumulated other comprehensive loss	(2,349)	(12)	[1]
Total stockholders' equity	283,659	291,031	[1]
Total liabilities and stockholders' equity	$ 347,955	$ 361,608	[1]

[1] Derived from December 31, 2011 audited financial statements.