Condensed Consolidated Statements of Cash Flows (unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net income	$ 24,036	$ 24,403
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,728	11,023
Provision for doubtful accounts	332	252
Provision for warranties	8,132	6,267
Deferred compensation provision	584	127
Sale (purchase) of trading securities, net	94	(1,475)
Stock-based compensation	693	643
Tax expense (benefit) from stock incentive plans	(498)	76
Deferred income tax benefit	(2,099)	(1,706)
Gain on disposition of fixed assets	(141)	(196)
(Increase) decrease in:
Trade and other receivables	(23,419)	(14,360)
Inventories	(13,117)	(10,087)
Prepaid expenses	2,021	(5,862)
Other assets	(2,470)	(2,088)
Increase (decrease) in:
Accounts payable	6,413	(434)
Accrued product warranty	(7,247)	(5,352)
Customer deposits	3,606	(2,027)
Prepaid and income taxes payable	698	(2,349)
Other	3,676	(3,765)
Net cash provided (used) by operating activities	13,022	(6,910)
Cash flows from investing activities:
Expenditures for property and equipment	(13,626)	(15,218)
Business acquisition, net of cash acquired	(34,965)	0
(Purchase) sale of short-term investments	16,249	(15,000)
Proceeds from sale of property and equipment	196	229
Net cash used by investing activities	(32,146)	(29,989)
Cash flows from financing activities:
Payment of dividends	(4,582)	(2,285)
Borrowings under bank loans	5,247	0
Tax (expense) benefit from stock issued under incentive plans	498	(76)
Supplemental Executive Retirement Plan transactions, net	(50)	(90)
Withholding tax paid upon vesting of restricted stock units	(938)	(783)
Proceeds from exercise of stock options	88	78
Sale of subsidiaries shares to minority shareholders, net	1,585	1,897
Net cash provided (used) by financing activities	1,848	(1,259)
Effect of exchange rates on cash	336	(1,614)
Net increase (decrease) in cash and cash equivalents	(16,940)	(39,772)
Cash and cash equivalents, beginning of period	35,564	80,929
Cash and cash equivalents, end of period	$ 18,624	$ 41,157