Consolidated Statements Of Cash Flows - Supplemental Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Information [Abstract]
Trade accounts receivable and other accounts receivable	$ 3,664	$ 49,215	$ (19,314)
Inventory	26,894	29,462	34,664
Energy commodity derivatives contracts, net of derivatives deposits	(606)	(7,583)	534
Accounts payable	4,107	(10,918)	2,002
Accrued payroll and benefits	3,466	6,055	9,809
Accrued interest payable	5,323	1,038	2,876
Accrued taxes other than income	3,699	9,094	5,485
Deferred revenue	10,485	7,978	16,793
Accrued product purchases	(13,016)	(18,678)	(9,016)
Current and noncurrent environmental liabilities	(4,904)	(2,144)	(12,247)
Other current and noncurrent assets and liabilities	9,250	22,208	(13,078)
Changes in components of operating assets and liabilities	$ 48,362	$ 85,727	$ 18,508