CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Cash Flows [Abstract]
Net Cash Provided by Operating Activities	$ 98,080	$ 34,936
Cash Flows from Investing Activities:
Capital Expenditures	(67,416)	(54,307)
Purchase of Available for Sale Securities	0	(6,059)
Proceeds from Restricted Investments	1,738	0
Net Proceeds from Sale of Restricted Investments in Margin Account	8,906	4,829
Investment in Long-Term Receivables	(3,142)	(4,658)
Proceeds from Long-Term Receivables	2,527	1,808
Notes Receivable	(50)	0
Purchase of Company-Owned Life Insurance	(357)	(356)
Investment in Affiliate	(3,079)	(717)
Advances on Notes Receivable - Affiliate	0	(1,265)
Repayment of Notes Receivable - Affiliate	1,626	275
Net Cash Used in Investing Activities	(59,247)	(60,450)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	(92,200)	26,700
Proceeds from Issuance of Long-Term Debt	61,000	0
Principal Repayments of Long-Term Debt	(12,905)	0
Proceeds from Sale of Common Stock	5,645	1,857
Net Cash (Used in) Provided by Financing Activities	(38,460)	28,557
Net Increase in Cash and Cash Equivalents	373	3,043
Cash and Cash Equivalents at Beginning of Period	3,877	4,171
Cash and Cash Equivalents at End of Period	$ 4,250	$ 7,214