Condensed Consolidated Statements of Cash Flows (unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net income	$ 22,687	$ 24,263
Adjustments to reconcile net income to net cash used by operating activities:
Depreciation and amortization	11,710	9,449
Provision for doubtful accounts	170	965
Provision for warranties	5,848	5,836
Deferred compensation provision (benefit)	(190)	446
Sale (purchase) of trading securities, net	(702)	1,025
Stock-based compensation	490	1,623
Tax benefit from stock incentive plans	(172)	(175)
Deferred income tax provision (benefit)	3,750	(1,573)
Asset impairment charge	0	2,170
(Gain) loss on disposition of fixed assets	(199)	24
(Increase) decrease in:
Trade and other receivables	(17,717)	(24,301)
Inventories	(26,919)	(28,171)
Prepaid expenses	(3,739)	1,021
Other assets	(878)	(1,763)
Increase (decrease) in:
Accounts payable	(3,346)	5,006
Accrued product warranty	(5,872)	(5,475)
Customer deposits	4,007	4,009
Other accrued liabilities	(691)	2,506
Net cash used by operating activities	(11,763)	(3,115)
Cash flows from investing activities:
Expenditures for property and equipment	(11,410)	(18,668)
Proceeds from sale of property and equipment	553	139
Net cash used by investing activities	(10,857)	(18,529)
Cash flows from financing activities:
Tax benefit from stock option exercise	172	175
Supplemental Executive Retirement Plan transactions, net	(130)	(137)
Withholding tax paid upon vesting of restricted stock units	(686)	0
Proceeds from exercise of stock options	492	510
Purchase of subsidiary shares from minority shareholders	(23)	0
Sale of subsidiaries shares to minority shareholders	1,030	0
Net cash provided by financing activities	855	548
Effect of exchange rates on cash	176	(11)
Net decrease in cash and cash equivalents	(21,589)	(21,107)
Cash and cash equivalents, beginning of period	57,505	94,597
Cash and cash equivalents, end of period	$ 35,916	$ 73,490