CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Cash Flows [Abstract]
Net Cash Provided by Operating Activities	$ 49,232	$ 55,886
Cash Flows from Investing Activities:
Capital Expenditures	(60,254)	(40,604)
Net Proceeds from Sale of Restricted Investments in Margin Account	7,444	7,931
Investment in Long-Term Receivables	(2,053)	(1,947)
Proceeds from Long-Term Receivables	1,981	2,402
Purchase of Company Owned Life Insurance	(230)	(372)
Investment in Affiliate	0	(1,076)
Advances on Notes Receivable - Affiliate	(342)	(498)
Repayment of Notes Receivable - Affiliate	3,228	58,249
Net Cash (Used in) Provided by Investing Activities	(50,226)	24,085
Cash Flows from Financing Activities:
Net Repayments of Short-Term Credit Facilities	(29,600)	(90,500)
Proceeds from Issuance of Long-Term Debt	30,000	0
Payments for Issuance of Long-Term Debt	(210)	(11)
Proceeds from Sale of Common Stock	5,157	7,244
Net Cash Provided by (Used in) Financing Activities	5,347	(83,267)
Net Increase (Decrease) in Cash and Cash Equivalents	4,353	(3,296)
Cash and Cash Equivalents at Beginning of Period	3,818	4,638
Cash and Cash Equivalents at End of Period	$ 8,171	$ 1,342