Consolidated Statements of Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Tax effect on pension and postretirement benefit adjustment	$ (98,973)	$ (11,083)	$ 61,702
Cash dividends declared, per share	$ 1.80	$ 1.64	$ 1.60
Tax effect on stock options exercised	5,356	3,251	684
Common Stock [Member]
Tax effect on stock options exercised	(5,356)	(3,251)	684
Additional Paid-in Capital [Member]
Tax effect on stock options exercised	(5,356)	(3,251)	684
Accumulated Other Comprehensive Loss [Member]
Tax effect on pension and postretirement benefit adjustment	(98,973)	(11,083)	61,702
Retained Earnings [Member]
Cash dividends declared, per share	$ 1.80	$ 1.64	$ 1.60
Total Parent Equity [Member]
Tax effect on pension and postretirement benefit adjustment	(98,973)	(11,083)	61,702
Cash dividends declared, per share	$ 1.80	$ 1.64	$ 1.60
Tax effect on stock options exercised	$ (5,356)	$ (3,251)	$ 684