Consolidated Statements Of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Income Statement [Abstract]
Net sales	$ 951,625		$ 1,004,165		$ 939,047		$ 864,647		$ 801,041		$ 821,175		$ 913,958		$ 1,034,867		$ 3,759,484	[1]	$ 3,571,041	[1]	$ 3,619,848	[1]
Cost of sales																	2,658,046		2,834,081		3,060,842
Gross profit	295,671		304,471		273,487		227,809		190,248		172,179		201,896		172,637		1,101,438		736,960		559,006
Selling, general and administrative expenses																	147,974		121,609		112,210
Income from operations	257,580		266,602		235,227		194,055		156,231		142,517		170,978		145,625		953,464		615,351		446,796
Other income (expense)
Interest expense																	(18,082)		(43,049)		(50,992)
Debt retirement costs																	0		(7,082)		0
Gain from sales of equity securities																	0		16,429		0
Other income, net																	6,790		3,520		5,628
Income before income taxes																	942,172		585,169		401,432
Provision for income taxes																	331,747		199,614		142,466
Net income	$ 170,972		$ 170,290		$ 145,816		$ 123,347		$ 95,277		$ 86,964		$ 115,501		$ 87,813		$ 610,425		$ 385,555		$ 258,966
Earnings per common share:
Basic	$ 2.56	[2]	$ 2.55	[2]	$ 2.18	[2]	$ 1.84	[2]	$ 1.43	[2]	$ 1.30	[2]	$ 1.73	[2]	$ 1.32	[2]	$ 9.13		$ 5.78		$ 3.89
Diluted	$ 2.54	[2]	$ 2.54	[2]	$ 2.17	[2]	$ 1.84	[2]	$ 1.42	[2]	$ 1.30	[2]	$ 1.72	[2]	$ 1.31	[2]	$ 9.09		$ 5.75		$ 3.87
Weighted average shares outstanding:
Basic																	66,612,128		66,289,429		65,927,421
Diluted																	66,889,625		66,641,495		66,300,158
Dividends per common share																	$ 0.8250		$ 4.2725		$ 0.2746

[1] Revenues are attributed to countries based on location of customer.

[2] Basic and diluted earnings per common share ("EPS") for each quarter is computed using the weighted average shares outstanding during that quarter, while EPS for the year is computed using the weighted average shares outstanding for the year. As a result, the sum of the EPS for each of the four quarters may not equal the EPS for the year.