Nature of Operations and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012 Y	Dec. 31, 2011	Dec. 31, 2010
Organization And Summary Of Significant Accounting Policies [Line Items]
Minimum percentage chance of tax benefit realization in final settlement	50.00%
Prior service costs from plan improvements amortization period, minimum, years	10
Prior service costs from plan improvements amortization period, maximum, years	20
Amortization period of internal and external development costs, years	7
Stock options and stock settled appreciation rights (SSARs) excluded from calculation of diluted shares	132,000	78,000
Difference amount between basic and diluted net income per share	$ 0.01	$ 0.01	$ 0.01
Percentage of total common shares outstanding	0.60%	0.60%	0.60%
Net income	$ 254,134,000	$ 266,866,000	$ 263,557,000
Non-cash effect of accrued capital expenditures		18,100,000
Allowance for doubtful accounts	2,100,000	2,100,000	2,100,000
Increase in gross trade accounts receivable		2,100,000
PRS [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Net income	$ 1,600,000	$ 1,700,000	$ 1,700,000
Minimum [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Other intangible assets amortized period, years	6 years
Minimum [Member] | Buildings And Improvements [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment, years	10 years
Minimum [Member] | Machinery and equipment [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment, years	3 years
Minimum [Member] | Information Technology Hardware And Software [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment, years	3 years
Maximum [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Other intangible assets amortized period, years	20 years
Maximum [Member] | Buildings And Improvements [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment, years	40 years
Maximum [Member] | Machinery and equipment [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment, years	10 years
Maximum [Member] | Information Technology Hardware And Software [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment, years	7 years