Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended															12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Line Items]
Total revenue	$ 573,048	$ 586,676	[1]	$ 498,427	[1]	$ 530,302	[1]	$ 678,193	[1]	$ 535,832	[1]	$ 512,435	[1]	$ 633,892	[1]	$ 2,188,453	$ 2,360,352	$ 1,947,730
Total costs and expenses	343,502	312,527	[1]	315,206	[1]	320,081	[1]	398,434	[1]	311,640	[1]	336,172	[1]	359,269	[1]	1,291,316	1,405,515	1,248,949
Operating margin (loss)	329,285	369,325		286,145		297,006		373,033		299,268		264,424		347,535		1,281,761	1,284,260	979,782
Net income	$ 207,123	$ 250,972		$ 177,391		$ 183,636		$ 252,085		$ 198,620		$ 146,260		$ 242,554		$ 819,122	$ 839,519	$ 582,237
Basic net income per limited partner unit (in dollars per unit)	$ 0.91	$ 1.10		$ 0.78		$ 0.81		$ 1.11		$ 0.87		$ 0.64		$ 1.07		$ 3.60	$ 3.69	$ 2.57
Diluted net income per limited partner unit (in dollars per unit)	$ 0.91	$ 1.10		$ 0.78		$ 0.81		$ 1.10		$ 0.87		$ 0.64		$ 1.07		$ 3.59	$ 3.69	$ 2.56
Revenue from Tender Deductions		$ 9,400		$ 10,900		$ 8,200		$ 11,100		$ 14,200		$ 16,000		$ 15,300
Lower-of-cost-or-market inventory adjustment								39,300								$ 5,000	$ 39,300
Derivative, Gain (Loss) on Derivative, Net								115,000
Sales [Member]
Quarterly Financial Data [Line Items]
Derivative, Gain (Loss) on Derivative, Net								111,600
Cost of Sales [Member]
Quarterly Financial Data [Line Items]
Derivative, Gain (Loss) on Derivative, Net								(14,000)
Operating Expense [Member]
Quarterly Financial Data [Line Items]
Derivative, Gain (Loss) on Derivative, Net								$ 17,400

[1] Includes adjustment of tender deductions as discussed in Note 2 – Summary of Significant Accounting Policies. The amounts adjusted for 2014 are as follows: first quarter $15.3 million; second quarter $16.0 million; third quarter $14.2 million; and fourth quarter $11.1 million. The amounts adjusted for 2015 are as follows: first quarter $8.2 million; second quarter $10.9 million; and third quarter $9.4 million.