Condensed Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
SALES	$ 355,780	$ 357,731
Costs and Expenses
Cost of sales	253,313	257,511
Selling and general expenses	19,619	16,433
Other operating income, net	(1,148)	(2,118)
Costs and Expenses, Total	271,784	271,826
Equity in income of New Zealand joint venture	13	1,673
OPERATING INCOME	84,009	87,578
Interest expense	(11,825)	(13,317)
Interest and miscellaneous (expense) income, net	(23)	293
INCOME BEFORE INCOME TAXES	72,161	74,554
Income tax expense	(18,724)	(16,142)
NET INCOME	53,437	58,412	276,005
OTHER COMPREHENSIVE INCOME (LOSS)
Foreign currency translation adjustment	5,825	288	3,546
New Zealand joint venture cash flow hedges	1,205	(567)	(2,373)
Amortization of gains/losses from pension and postretirement plans, net of income tax expense of $1,368 and $928	3,140	2,093	(46,263)
Total other comprehensive income	10,170	1,814
COMPREHENSIVE INCOME	$ 63,607	$ 60,226
EARNINGS PER COMMON SHARE (Note 2)
Basic earnings per share	$ 0.44	$ 0.48
Diluted earnings per share	$ 0.42	$ 0.47
Dividends per share	$ 0.40	$ 0.36	$ 1.52