Condensed Consolidated Statements of Cash Flows (unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 24,403	$ 22,687
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Depreciation and amortization	11,023	11,710
Provision for doubtful accounts	252	170
Provision for warranties	6,267	5,848
Deferred compensation provision (benefit)	127	(190)
Purchase of trading securities, net	(16,475)	(702)
Stock-based compensation	643	490
Tax expense (benefit) from stock incentive plans	76	(172)
Deferred income tax provision (benefit)	(1,706)	3,750
Gain on disposition of fixed assets	(196)	(199)
(Increase) decrease in:
Trade and other receivables	(14,360)	(17,717)
Inventories	(10,087)	(26,919)
Prepaid expenses	(5,862)	1,001
Other assets	(2,088)	(878)
Increase (decrease) in:
Accounts payable	(434)	(3,346)
Accrued product warranty	(5,352)	(5,872)
Customer deposits	(2,027)	4,007
Prepaid and income taxes payable	(2,349)	(4,740)
Other current liabilities	(3,765)	(691)
Net cash used by operating activities	(21,910)	(11,763)
Cash flows from investing activities:
Expenditures for property and equipment	(15,218)	(11,410)
Proceeds from sale of property and equipment	229	553
Net cash used by investing activities	(14,989)	(10,857)
Cash flows from financing activities:
Payment of dividends	(2,285)	0
Tax (expense) benefit from stock option exercise	(76)	172
Supplemental Executive Retirement Plan transactions, net	(90)	(130)
Withholding tax paid upon vesting of restricted stock units	(783)	(686)
Proceeds from exercise of stock options	78	492
Sale of subsidiaries shares to minority shareholders	1,897	1,030
Purchase of subsidiary shares from minority shareholders	0	(23)
Net cash provided (used) by financing activities	(1,259)	855
Effect of exchange rates on cash	(1,614)	176
Net decrease in cash and cash equivalents	(39,772)	(21,589)
Cash and cash equivalents, beginning of period	80,929	57,505
Cash and cash equivalents, end of period	$ 41,157	$ 35,916