CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Net income	$ 17,540	$ 69,731	$ 49,239
Other comprehensive (loss) income
Employee pension plan adjustments, net of taxes	(1,968)	153	882
Comprehensive income	$ 15,572	$ 69,884	$ 50,121

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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-Glossary Other Comprehensive Income

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-Name Emerging Issues Task Force (EITF)

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Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Glossary Net Income

-URI http://asc.fasb.org/extlink&oid=6518256

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-Name Regulation S-X (SX)

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+ Details

- Definition

The increase (decrease) to accumulated comprehensive income during the period related to benefit plans, after tax, attributable to the parent entity.

+ References

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

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+ Details

- Definition

This element represents Other Comprehensive Income or Loss, Net of Tax, for the period. Includes deferred gains or losses on qualifying hedges, unrealized holding gains or losses on available-for-sale securities, minimum pension liability, and cumulative translation adjustment. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Name Accounting Principles Board Opinion (APB)

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+ Details