Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income (loss)	$ 37,579	$ (20,552)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	13,139	13,880
Provision for doubtful accounts	806	148
Provision for warranties	4,496	7,529
Deferred compensation expense	144	99
Stock-based compensation	1,739	1,321
Deferred income tax provision (benefit)	8,412	(121)
(Gain) loss on disposition of fixed assets	176	(183)
Distributions to SERP participants	(1,007)	(184)
Change in operating assets and liabilities:
Sale (purchase) of trading securities, net	50	(336)
Trade and other receivables	(6,719)	(24,219)
Inventories	(5,240)	(3,410)
Prepaid expenses	911	2,278
Other assets	(347)	(3,639)
Accounts payable	(2,006)	4,181
Accrued pellet plant agreement costs	0	68,000
Accrued product warranty	(5,287)	(11,482)
Customer deposits	(13,025)	(4,163)
Prepaid and income taxes payable, net	7,669	(9,141)
Other	1,381	(1,585)
Net cash provided by operating activities	42,871	18,421
Cash flows from investing activities:
Expenditures for property and equipment	(8,657)	(8,719)
Proceeds from sale of property and equipment	136	243
Other	433	95
Net cash used by investing activities	(8,088)	(8,381)
Cash flows from financing activities:
Payment of dividends	(4,956)	(4,618)
Borrowings under bank loans	121,041	0
Repayments of bank loans	(152,055)	(1,105)
Sale of Company shares held by SERP	238	279
Withholding tax paid upon vesting of restricted stock units	(160)	(432)
Purchase of subsidiary shares	(16)	(27)
Net cash used by financing activities	(35,908)	(5,903)
Effect of exchange rates on cash	209	(1,211)
Net change in cash and cash equivalents	(916)	2,926
Cash and cash equivalents, beginning of period	25,821	62,280
Cash and cash equivalents, end of period	$ 24,905	$ 65,206