Schedule of Business Acquisitions, by Acquisition (Details) - USD ($) $ 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
Business Combination and Asset Acquisition [Line Items]
Revenues	$ 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
Operating Income (Loss)																963,620	974,231	705,056
Net income	$ 207,123	$ 250,972		$ 177,391		$ 183,636		$ 252,085		$ 198,620		$ 146,260		$ 242,554		$ 819,122	$ 839,519	582,237
Business Acquisition, Pro Forma Revenue																		1,974,440
Business Acquisition, Pro Forma Net Income (Loss)																		588,583
Plains Pipeline Acquisition [Member]
Business Combination and Asset Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment																		192,422
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other																		2,048
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other																		(2,470)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest																		192,000
Revenues																		12,661
Operating Income (Loss)																		$ 6,400

[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.