Description of the Business and Summary of Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Inventories
Raw materials	$ 594,388,000	$ 609,150,000
Supplies	278,494,000	251,716,000
Work-in-progress	82,934,000	106,609,000
Finished goods	246,691,000	232,109,000
Total inventories	1,202,507,000	1,199,584,000
Investments
Investments	22,700,000	24,900,000
Property, plant and equipment
Property, plant and equipment	3,761,759,000	3,551,561,000
Less accumulated depreciation	1,530,561,000	1,357,816,000
Property, plant and equipment, net	2,231,198,000	2,193,745,000
Depreciation expense	179,900,000	176,500,000	171,700,000
Minimum
Property, plant and equipment
Ownership percentage of equity method investment	49.00%
Maximum
Property, plant and equipment
Ownership percentage of equity method investment	50.00%
Land and improvements
Property, plant and equipment
Property, plant and equipment	288,360,000	271,208,000
Buildings and improvements
Property, plant and equipment
Property, plant and equipment	524,530,000	496,976,000
Buildings and improvements | Minimum
Property, plant and equipment
Property, plant and equipment useful life	10 years
Buildings and improvements | Maximum
Property, plant and equipment
Property, plant and equipment useful life	40 years
Plant, machinery and equipment
Property, plant and equipment
Property, plant and equipment	2,810,106,000	2,656,358,000
Plant, machinery and equipment | Minimum
Property, plant and equipment
Property, plant and equipment useful life	3 years
Plant, machinery and equipment | Maximum
Property, plant and equipment
Property, plant and equipment useful life	15 years
Construction in progress
Property, plant and equipment
Property, plant and equipment	$ 138,763,000	$ 127,019,000