Condensed Consolidated Statements of Cash Flows (unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net income	$ 24,263	$ 19,162
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	9,449	9,570
Provision for (recoveries of) doubtful accounts	965	(11)
Provision for inventory reserve	2,078	2,465
Provision for warranty	5,836	6,954
Deferred compensation provision	446	67
Sale of trading securities, net	1,025	654
Stock-based compensation	1,623	815
Tax benefit from stock incentive plans	(175)	(329)
Deferred income tax benefit	(1,573)	(1,171)
Asset impairment charge	2,170	0
Loss on disposition of fixed assets	24	55
(Increase) decrease in:
Trade and other receivables	(24,301)	(16,517)
Inventories	(30,249)	20,115
Prepaid expenses	1,021	8,335
Other assets	(1,763)	(241)
Increase (decrease) in:
Accounts payable	5,006	1,081
Accrued product warranty	(5,475)	(6,986)
Customer deposits	4,009	1,516
Income taxes payable	328	1,430
Other accrued liabilities	2,178	(1,875)
Net cash provided (used) by operating activities	(3,115)	45,089
Cash flows from investing activities:
Expenditures for property and equipment	(18,668)	(3,759)
Proceeds from sale of property and equipment	139	71
Net cash used by investing activities	(18,529)	(3,688)
Cash flows from financing activities:
Tax benefit from stock option exercise	175	329
Supplemental Executive Retirement Plan transactions, net	(137)	(136)
Proceeds from exercise of stock options	510	763
Net cash provided by financing activities	548	956
Effect of exchange rates on cash	(11)	(797)
Net increase (decrease) in cash and cash equivalents	(21,107)	41,560
Cash and cash equivalents, beginning of period	94,597	40,429
Cash and cash equivalents, end of period	$ 73,490	$ 81,989