Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statements of Comprehensive Income [Abstract]
Unrecognized actuarial loss and prior service cost, income taxes	$ 240	$ 111
Income tax on cash flow hedge activity	$ 38	$ 57

Total tax effect of the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges after taxes. The change includes an entity's share of an equity investee's increase (decrease) in deferred hedging gains or losses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 25

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