CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Net sales	$ 178,229	$ 147,906	$ 715,631	$ 714,127
Cost of sales	118,820	144,106	430,134	475,303
Gross profit	59,409	3,800	285,497	238,824
Operating expenses:
Selling expense	49,871	60,273	179,851	212,822
General and administrative expense	18,870	18,238	48,626	48,918
Research and development expense	7,689	7,978	22,435	22,381
Total operating expenses	76,430	86,489	250,912	284,121
Income (loss) from operations	(17,021)	(82,689)	34,585	(45,297)
Other income (expense), net	(3,095)	(3,359)	934	(4,246)
Income (loss) before income taxes	(20,116)	(86,048)	35,519	(49,543)
Income tax provision	1,037	750	4,941	2,654
Net income (loss)	(21,153)	(86,798)	30,578	(52,197)
Dividends on convertible preferred stock	(1,766)	(2,414)	(3,332)	(7,664)
Net income (loss) allocable to common shareholders	$ (22,919)	$ (89,212)	$ 27,246	$ (59,861)
Earnings (loss) per common share:
Basic	$ (0.32)	$ (1.33)	$ 0.38	$ (0.91)
Diluted	$ (0.32)	$ (1.33)	$ 0.36	$ (0.91)
Weighted-average common shares outstanding:
Basic	72,649	67,162	71,613	65,740
Diluted	72,649	67,162	86,870	65,740