Condensed Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Net sales	$ 202,223	$ 209,275	$ 352,902	$ 399,520
Cost of sales	163,564	143,540	288,821	289,341
Gross profit	38,659	65,735	64,081	110,179
Selling, general and administrative expense	25,125	22,886	49,616	44,277
Provisions for losses on accounts receivable	166	83	266	123
Other expense	1,726	555	3,756	722
Other income	(583)	(112)	(1,545)	(348)
Operating income	12,225	42,323	11,988	65,405
Interest expense	536	1,179	1,267	2,311
Non-operating other expense (income), net	8	(267)	24	(272)
Income from continuing operations before provisions for income taxes and equity in earnings of affiliate	11,681	41,411	10,697	63,366
Provisions for income taxes	4,367	15,451	3,622	23,253
Equity in earnings of affiliate	(172)	(170)	(343)	(341)
Income from continuing operations	7,486	26,130	7,418	40,454
Net loss from discontinued operations	59	97	59	118
Net income	7,427	26,033	7,359	40,336
Dividends on preferred stocks			300	300
Net income applicable to common stock	$ 7,427	$ 26,033	$ 7,059	$ 40,036
Weighted-average common shares:
Basic	22,437,485	22,340,826	22,430,589	22,332,303
Diluted	23,577,383	23,509,330	22,914,660	23,516,425
Income per common share:
Basic	$ 0.33	$ 1.17	$ 0.31	$ 1.79
Diluted	$ 0.31	$ 1.11	$ 0.31	$ 1.72