CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Operating activities:
Net income	$ 39,305	$ 95,826	$ 81,082	$ 200,056
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	55,502	56,257	111,074	111,003
Equity-based compensation	2,602	3,812	8,725	7,522
Deferred income taxes	10,634	9,028	19,831	21,963
(Gain) loss on disposal of property, plant and equipment	326	139	(413)	96
Changes in certain assets and liabilities:
Accounts receivable	73,734	34,536	12,914	(227,212)
Inventories	18,787	(9,026)	(36,303)	(81,133)
Other assets	(393)	2,315	2,567	5,697
Accounts payable	(60,837)	2,750	(25,935)	96,925
Income taxes receivable/payable	(26,468)	(17,119)	(9,076)	28,320
Accrued expenses	(12,590)	(12,521)	(42,446)	6,697
Net cash provided by operating activities	100,602	165,997	122,020	169,934
Investing activities:
Purchases of property, plant and equipment	(54,789)	(34,976)	(100,344)	(53,669)
Proceeds from maturity of short-term commercial paper	54,984		74,832
Other investing activities	678	2,142	(21,034)	999
Net cash provided by (used in) investing activities	873	(32,834)	(46,546)	(52,670)
Financing activities:
Issuance of current and long-term debt			289,969	5,126
Repayment of current and long-term debt	(21,896)	(491)	(305,344)	(7,816)
Debt issuance costs			(2,188)
Proceeds from exercise of stock options, including related tax effect	341	4,569	1,438	12,865
Contributions from noncontrolling investors, net	5,117	1,470	14,623	1,887
Dividends paid	(21,908)	(21,830)	(43,795)	(38,148)
Net cash used in financing activities	(38,346)	(16,282)	(45,297)	(26,086)
Increase in cash and equivalents	63,129	116,881	30,177	91,178
Cash and equivalents at beginning of period	357,809	160,810	390,761	186,513
Cash and equivalents at end of period	420,938	277,691	420,938	277,691
Supplemental disclosure information:
Cash paid for interest	62,807	71,047	81,560	86,157
Cash paid for federal and state income taxes, net	$ 41,302	$ 60,455	$ 40,347	$ 61,975