Supplemental Disclosures to the Statements of Cash Flows (Details Textual) (USD $)	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010
Supplemental Disclosures to the Statements of Cash Flows (Textuals) [Abstract]
Unpaid change in liabilities for investing activities	$ 10,763,000	$ 14,645,000
Unpaid capital expenditures	18,762,000	19,894,000
Net of capitalized	$ 4,072,000	$ 1,315,000

Supplemental Disclosures to the Statements of Cash Flows.

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- Definition

Future cash outflow to pay for purchases of fixed assets that have occurred.

+ Details

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- Definition

The amount of cash paid during the current period for interest owed on money borrowed that is not charged as an expense but rather is capitalized based on the long term nature of the use of the borrowed funds.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 29

+ Details

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- Definition

Net change in the amount of noncurrent deferred charges, classified as investing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 17

+ Details

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