Debt (Narrative) (Details) (USD $)	12 Months Ended						12 Months Ended			12 Months Ended			12 Months Ended						12 Months Ended			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Letter Of Credit [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member]	Jul. 25, 2012 Senior Secured Credit Facility [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Crude Oil And Petroleum Products Inventory [Member]	Jul. 25, 2012 Senior Secured Credit Facility [Member] Crude Oil And Petroleum Products Inventory [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Letter Of Credit [Member]	Jul. 25, 2012 Senior Secured Credit Facility [Member] Accordion [Member]	Feb. 01, 2012 Senior Unsecured Notes [Member]	Dec. 31, 2013 Seven Point Eight Seventy Five Percentage Senior Unsecured Notes [Member]	Feb. 01, 2012 Seven Point Eight Seventy Five Percentage Senior Unsecured Notes [Member]	Nov. 30, 2010 Seven Point Eight Seventy Five Percentage Senior Unsecured Notes [Member]	Dec. 31, 2013 Federal Funds Effective Rate [Member]	Dec. 31, 2013 Eurodollar Rate [Member]	Dec. 31, 2013 Applicable Margin [Member]	Dec. 31, 2013 Five Point Seventy Five Percentage Senior Unsecured Notes [Member]	Feb. 08, 2013 Five Point Seventy Five Percentage Senior Unsecured Notes [Member]	Dec. 31, 2013 CHOPS [Member]	Dec. 31, 2013 Maximum [Member]	Dec. 31, 2013 Maximum [Member] Senior Secured Credit Facility [Member]	Dec. 31, 2013 Maximum [Member] Senior Secured Credit Facility [Member] Letter Of Credit [Member]	Dec. 31, 2013 Maximum [Member] Federal Funds Effective Rate [Member]	Dec. 31, 2013 Maximum [Member] LIBOR Rate [Member]	Dec. 31, 2013 Maximum [Member] Eurodollar Rate [Member]	Dec. 31, 2013 Maximum [Member] Alternate Base Rate [Member]	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Minimum [Member] Senior Secured Credit Facility [Member]	Dec. 31, 2013 Minimum [Member] Eurodollar Rate [Member]	Dec. 31, 2013 Minimum [Member] Alternate Base Rate [Member]	Dec. 31, 2013 During Acquisition Period [Member] Maximum [Member] Senior Secured Credit Facility [Member]	Dec. 31, 2013 During Acquisition Period [Member] Minimum [Member] Senior Secured Credit Facility [Member]	Jul. 25, 2012 Amended Facility [Member] Senior Secured Credit Facility [Member] Crude Oil And Petroleum Products Inventory [Member]	Jul. 25, 2012 Amended Facility [Member] Senior Secured Credit Facility [Member] Accordion [Member]	Dec. 31, 2013 Amended Facility [Member]
Debt Instrument [Line Items]
Senior secured credit facility, maximum borrowing capacity				$ 775,000,000		$ 125,000,000		$ 225,000,000																								$ 150,000,000	$ 300,000,000	$ 1,000,000,000
Line of credit facility, aggregate maximum borrowing capacity				1,300,000,000
Interest rate spreads senior secured credit facility													0.50%	2.00%	1.00%							1.00%	1.00%
Letter of credit, fee percentage		2.00%																						2.75%	1.75%			1.75%	0.75%
Commitment fee percentage	0.375%																		0.50%							0.375%
Debt instrument covenant, requirement leverage ratio																				1.00							5.00			1.00	5.50
Debt instrument covenant, requirement senior secured leverage ratio																				1.00							3.75			1.00	4.25
Debt instrument covenant, requirement interest coverage ratio																				1.00							3.00			1.00	2.75
Senior secured credit facility, amount outstanding			582,800,000		80,800,000
Letters of credit, outstanding amount							11,900,000														100,000,000
Maturity date of debt							Jul. 25, 2017			Dec. 15, 2018						Feb. 15, 2021
Total amount available for borrowings, remaining borrowing capacity			405,300,000
Debt instrument, principal amount									$ 350,000,000		$ 100,000,000	$ 250,000,000					$ 350,000,000
Debt instrument, stated rate												7.875%					5.75%
Debt instrument, percentage of face value									101.00%
Debt instrument, effective interest rate									7.682%
Ownership percentage																		50.00%
Maximum percentage of principal, early debt redemption																35.00%
Percentage of the redeemable value of debt on Face amount																105.75%