Condensed Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
SALES	$ 371,926	$ 357,397	$ 727,706	$ 715,127
Costs and Expenses
Cost of sales	262,555	262,772	515,868	520,283
Selling and general expenses	16,250	15,992	35,868	32,425
Other operating (income) expense, net	(5,299)	709	(6,446)	(1,409)
Costs and Expenses, Total	273,506	279,473	545,290	551,299
Equity in income of New Zealand joint venture	170	1,149	184	2,823
OPERATING INCOME	98,590	79,073	182,600	166,651
Interest expense	(16,056)	(12,628)	(27,880)	(25,945)
Interest and miscellaneous income, net	85	314	59	605
INCOME BEFORE INCOME TAXES	82,619	66,759	154,779	141,311
Income tax expense	(13,540)	(10,305)	(32,264)	(26,446)
NET INCOME	69,079	56,454	122,515	114,865	276,005
OTHER COMPREHENSIVE (LOSS) INCOME
Foreign currency translation adjustment	(8,081)	7,442	(2,255)	7,729	3,546
New Zealand joint venture cash flow hedges	(1,998)	699	(793)	132	(2,373)
Amortization of losses from pension and postretirement plans, net of income tax expense of $1,482, $927, $2,850 and $1,854	3,401	2,094	6,541	4,188	(46,263)
Total other comprehensive (loss) income	(6,678)	10,235	3,493	12,049
COMPREHENSIVE INCOME	$ 62,401	$ 66,689	$ 126,008	$ 126,914
EARNINGS PER COMMON SHARE (Note 2)
Basic earnings per share	$ 0.56	$ 0.46	$ 1.00	$ 0.94
Diluted earnings per share	$ 0.54	$ 0.45	$ 0.96	$ 0.92
Dividends per share	$ 0.40	$ 0.36	$ 0.80	$ 0.72	$ 1.52