Quarterly Financial Data (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Quarterly Financial Data (Unaudited) [Abstract]
Net sales	$ 270,422	$ 503,584	$ 706,423	$ 312,889	$ 241,426	$ 455,020	$ 647,467	$ 269,833	$ 1,793,318	$ 1,613,746	$ 1,539,794
Gross profit	80,835	147,906	211,439	91,410	73,567	130,869	190,534	76,292	531,590	471,262	449,724
Net income (loss)	$ (10,115)	$ 24,169	$ 58,577	$ (638)	$ (11,805)	$ 22,784	$ 52,770	$ (6,111)	$ 71,993	$ 57,638	$ 19,202
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.21)	$ 0.50	$ 1.21	$ (0.01)	$ (0.24)	$ 0.46	$ 1.07	$ (0.12)	$ 1.49	$ 1.17	$ 0.39
Diluted (in dollars per share)	$ (0.21)	$ 0.50	$ 1.19	$ (0.01)	$ (0.24)	$ 0.45	$ 1.05	$ (0.12)	$ 1.47	$ 1.15	$ 0.39