CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Net Cash Provided by Operating Activities	$ 67,738	$ 73,839
Cash Flows from Investing Activities:
Capital Expenditures	(92,776)	(88,992)
Net Proceeds from Sale of Restricted Investments in Margin Accounts	1,712	(4,466)
Investment in Long-Term Receivables	(3,780)	(2,009)
Proceeds from Long-Term Receivables	4,297	1,213
Net Cash Used in Investing Activities	(90,547)	(94,254)
Cash Flows from Financing Activities:
Net Borrowing from (Repayment of) Lines of Credit	47,600	(4,100)
Proceeds from Issuance of Long-Term Debt	0	60,000
Payments for Issuance of Long-Term Debt	(32)	(1,016)
Principal Repayments of Long-Term Debt	(25,000)	0
Dividend on Common Stock	0	(35,001)
Net Cash Provided in Financing Activities	22,568	19,883
Net Decrease in Cash and Cash Equivalents	(241)	(532)
Cash and Cash Equivalents at Beginning of Period	2,030	1,993
Cash and Cash Equivalents at End of Period	$ 1,789	$ 1,461