Debt, Accounts Receivable Sales Facility and Capitalized Interest (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Credit Facilities [Member] VLP Revolver [Member]	Jun. 30, 2013 Credit Facilities [Member] VLP Revolver [Member]	Jun. 30, 2014 Credit Facilities [Member] A/R Sales Facility [Member]	Jun. 30, 2013 Credit Facilities [Member] A/R Sales Facility [Member]	Dec. 31, 2013 Credit Facilities [Member] A/R Sales Facility [Member]
Line of Credit Facility [Line Items]
Proceeds from Long-term Lines of Credit					$ 0	$ 0
Accounts Receivable Sales Facility (Textual)
Line of credit facility, maximum borrowing capacity					300,000,000		1,500,000,000
Maturity date of accounts receivable sales facility					Dec. 31, 2018		Jul. 31, 2015
Proceeds from accounts receivable sales facility							0	0
Repayments under accounts receivable sales facility							0	0
Amount outstanding							100,000,000		100,000,000
Capitalized Interest (Textual)
Interest costs incurred, capitalized	18,000,000	45,000,000	35,000,000	85,000,000
Repayments of Long-term Lines of Credit					$ 0	$ 0