CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Net Cash Provided by Operating Activities	$ 56,213	$ 121,982
Cash Flows from Investing Activities:
Capital Expenditures	(96,891)	(67,778)
Net (Purchase of) Proceeds from Restricted Investments in Margin Account	7,775	3,380
Investment in Long-Term Receivables	(2,871)	(2,390)
Proceeds from Long-Term Receivables	3,781	2,418
Purchase of Company Owned Life Insurance	(3,525)	(3,525)
Investment in Affiliate	(28,979)	(21,867)
Advances on Notes Receivable - Affiliate	(58,178)	(24,108)
Repayment of Notes Receivable - Affiliate	4,681	38,713
Other	(584)	(5,180)
Net Cash Used in Investing Activities	(174,791)	(80,337)
Cash Flows from Financing Activities:
Net Borrowings from (Repayments of) Short-Term Credit Facilities	1,900	(55,650)
Proceeds from Issuance of Long-Term Debt	150,000	0
Principal Repayments of Long-Term Debt	(35,000)	0
Payments for Issuance of Long-Term Debt	(583)	(28)
Premium for Early Retirement of Debt	(700)	0
Dividends on Common Stock	(12,200)	(10,933)
Proceeds from Sale of Common Stock	9,256	0
Proceeds from Finance Obligation	0	23,425
Net Cash Provided by (Used in) Financing Activities	112,673	(43,186)
Net Decrease in Cash and Cash Equivalents	(5,905)	(1,541)
Cash and Cash Equivalents at Beginning of Period	7,538	2,363
Cash and Cash Equivalents at End of Period	$ 1,633	$ 822