CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Statement of Cash Flows [Abstract]
Net Cash Provided by Operating Activities	$ 89,669	$ 62,509
Cash Flows from Investing Activities:
Capital Expenditures	(134,945)	(88,305)
Net Proceeds from Sale of (Purchase of) Restricted Investments in Margin Account	3,333	(13,840)
Purchase of Restricted Investments with Escrowed Loan Proceeds	0	(40)
Investment in Long-Term Receivables	(3,410)	(3,256)
Proceeds from Long-Term Receivables	3,536	3,433
Purchase of Company Owned Life Insurance	(526)	(3,785)
Investment in Affiliate	0	(2,492)
Advances on Notes Receivable - Affiliate	(1,922)	(6,157)
Repayment of Notes Receivable - Affiliate	5,639	94,360
Net Cash Used in Investing Activities	(128,295)	(20,082)
Cash Flows from Financing Activities:
Net Repayments of Short-Term Credit Facilities	(147,200)	(43,200)
Proceeds from Issuance of Long-Term Debt	189,000	0
Payments for Issuance of Long-Term Debt	(1,204)	(5)
Dividends on Common Stock	(15,510)	(14,102)
Proceeds from Sale of Common Stock	17,119	12,502
Net Cash Provided by (Used in) Financing Activities	42,205	(44,805)
Net Increase (Decrease) in Cash and Cash Equivalents	3,579	(2,378)
Cash and Cash Equivalents at Beginning of Period	3,818	4,638
Cash and Cash Equivalents at End of Period	$ 7,397	$ 2,260