Shareholders' Equity (Details) (USD $)	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent, Period Start						$ 1,251,582,000					$ 1,146,206,000		$ 1,251,582,000	$ 1,146,206,000	$ 938,937,000
Net income	56,230,000	[1]	104,909,000	[2]	56,454,000	58,412,000	59,171,000	[3]	62,904,000	38,558,000	56,953,000	[4]	276,005,000	217,586,000	312,541,000
Dividends													(186,828,000)	(164,514,000)	(158,486,000)
Issuance of shares under incentive stock plans													13,451,000	26,314,000	11,115,000
Equity portion of convertible debt															8,850,000
Exchangeable Notes Hedge Purchased and Warrants Sold															(2,391,000)
Share-based compensation													16,181,000	15,223,000	15,754,000
Excess tax benefit on stock-based compensation													5,681,000	5,411,000	2,720,000
Repurchase of common shares													(7,909,000)	(6,028,000)	(1,388,000)
Net gain (loss) from pension and postretirement plans													(46,263,000)	6,385,000	4,879,000
Foreign currency translation adjustment													3,546,000	4,162,000	15,980,000
New Zealand joint venture cash flow hedges													(2,373,000)	837,000	(2,305,000)
Stockholders' Equity Attributable to Parent, Period End	1,323,073,000						1,251,582,000						1,323,073,000	1,251,582,000	1,146,206,000
Dividends [Abstract]
Common Stock, Dividends, Per Share, Taxable as Capital Gains													1.52	1.36	1.03
Common Stock, Dividends, Per Share, Non-taxable															0.30
Common Stock, Dividends, Per Share, Declared													$ 1.52	$ 1.36	$ 1.33
Common Stock Including Additional Paid in Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent, Period Start						602,882,000					561,962,000		602,882,000	561,962,000	527,302,000
Shares, Issued						121,023,140					119,312,961		121,023,140	119,312,961	118,221,646
Issuance of shares under incentive stock plans													13,451,000	26,314,000	11,115,000
Issuance of shares under incentive stock plans, Shares													1,220,731	1,914,341	1,165,358
Equity portion of convertible debt															8,850,000
Exchangeable Notes Hedge Purchased and Warrants Sold															(2,391,000)
Share-based compensation													16,181,000	15,223,000	15,754,000
Excess tax benefit on stock-based compensation													5,681,000	5,411,000	2,720,000
Repurchase of common shares													(7,909,000)	(6,028,000)	(1,388,000)
Stock repurchased during period, Shares													(208,694)	(204,162)	(74,043)
Stockholders' Equity Attributable to Parent, Period End	630,286,000						602,882,000						630,286,000	602,882,000	561,962,000
Shares, Issued	122,035,177						121,023,140						122,035,177	121,023,140	119,312,961
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent, Period Start						717,058,000					663,986,000		717,058,000	663,986,000	509,931,000
Net income													276,005,000	217,586,000	312,541,000
Dividends													(186,828,000)	(164,514,000)	(158,486,000)
Stockholders' Equity Attributable to Parent, Period End	806,235,000						717,058,000						806,235,000	717,058,000	663,986,000
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent, Period Start						(68,358,000)					(79,742,000)		(68,358,000)	(79,742,000)	(98,296,000)
Net gain (loss) from pension and postretirement plans													(46,263,000)	6,385,000	4,879,000
Foreign currency translation adjustment													3,546,000	4,162,000	15,980,000
New Zealand joint venture cash flow hedges													(2,373,000)	837,000	(2,305,000)
Stockholders' Equity Attributable to Parent, Period End	$ (113,448,000)						$ (68,358,000)						$ (113,448,000)	$ (68,358,000)	$ (79,742,000)

[1] Fourth quarter 2011 included a pre-tax $6.5 million ($4.1 million after tax) increase in a disposition reserve.

[2] Third quarter 2011 included a benefit of $16.0 million from the reversal of a reserve related to the taxability of the AFMC.

[3] Fourth quarter 2010 included a tax benefit of $24.3 million related to the CBPC. See Note 8 — Income Taxes.

[4] First quarter 2010 included a pre-tax $12.4 million ($11.5 million after tax) gain from the sale of a portion of the Company's interest in its New Zealand JV. See Note 5 — Joint Venture Investment for further information.