CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities
Net income (loss)	$ (60,744)	$ 37,590	$ 54,988
Adjustments to reconcile net income (loss) to net cash provided (used) by operating activities:
Depreciation	22,411	21,312	20,818
Amortization	5,502	4,490	3,995
Provision for doubtful accounts	223	482	280
Provision for warranties	13,219	16,725	18,912
Deferred compensation provision (benefit)	(1,554)	(574)	1,742
Deferred income tax benefit	(25,385)	(291)	(3,521)
Gain on disposition of fixed assets	(71)	(388)	(224)
Stock-based compensation	2,182	3,142	2,936
Restructuring and asset impairment charges	13,060	0	0
Distributions to SERP participants	(767)	(206)	(532)
Change in operating assets and liabilities, net of effects of acquisitions:
Sale (purchase) of trading securities, net	(758)	473	(1,873)
Trade and other receivables	(16,189)	(7,749)	(4,895)
Inventories	30,757	(19,618)	30,839
Prepaid expenses	(11,943)	(5,181)	4,846
Other assets	(3,698)	(779)	2,069
Accounts payable	9,843	630	8,836
Customer deposits	(522)	9,379	(762)
Accrued product warranty	(17,539)	(14,642)	(15,125)
Income taxes payable	3,683	(597)	181
Accrued retirement benefit costs	(1,100)	45	(50)
Accrued loss reserves	(125)	122	229
Other accrued liabilities	8,887	(1,118)	11,142
Other	843	(1,366)	(25)
Net cash provided (used) by operating activities	(29,785)	41,881	134,806
Cash Flows from Investing Activities
Business acquisition, net of cash acquired	0	(26,443)	(39,764)
Proceeds from sale of property and equipment	375	480	614
Expenditures for property and equipment	(27,440)	(20,046)	(27,367)
Sale (purchase) of investments	(360)	(891)	290
Net cash used by investing activities	(27,425)	(46,900)	(66,227)
Cash Flows from Financing Activities
Payment of dividends	(9,625)	(9,226)	(9,217)
Borrowings under bank loans	148,504	0	5,973
Repayment of bank loans	(91,964)	(7,242)	(5,903)
Purchase of shares of subsidiaries	(28)	(106)	(696)
Sale (purchase) of Company shares by SERP, net	377	289	(153)
Withholding tax paid upon vesting of restricted stock units	(432)	(507)	(1,024)
Repurchase of Company stock	(24,138)	0	0
Net cash provided (used) by financing activities	22,694	(16,792)	(11,020)
Effect of exchange rates on cash	(1,943)	1,720	(250)
Increase (decrease) in cash and cash equivalents	(36,459)	(20,091)	57,309
Cash and cash equivalents, beginning of year	62,280	82,371	25,062
Cash and cash equivalents, end of year	25,821	62,280	82,371
Cash paid during the year for:
Interest	856	588	1,407
Income taxes, net of refunds	$ 8,523	$ 26,917	$ 28,455