Related-Party Transactions Related-Party Transactions, Affiliate Agreements (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended	0 Months Ended						0 Months Ended
	Dec. 31, 2013 Amended Omnibus Agreement	Jul. 01, 2014 Subsequent Event Nikiski TSA option	Jul. 01, 2014 Subsequent Event Anacortes TSA option	Jul. 01, 2014 Subsequent Event Martinez TSA option	Jul. 01, 2014 Subsequent Event SSA option	Jul. 01, 2014 Subsequent Event Construction Agreement	Jul. 01, 2014 Subsequent Event Construction Agreement	Jul. 01, 2014 Subsequent Event Amended Omnibus Agreement	Jul. 01, 2014 Subsequent Event Amended Omnibus Agreement
Related Party Transaction [Line Items]
Agreement term (years)		10 years	10 years	10 years	10 years
Effective date		Jul. 01, 2014	Jul. 01, 2014	Jul. 01, 2014	Jul. 01, 2014	Jul. 01, 2014		Jul. 01, 2014
Agreement date						Jul. 28, 2014
Agreement amendment date								Jul. 01, 2014
Number of contract renewals (options)		2	2	2	2
Term of renewal (years)		5 years	5 years	5 years	5 years
Fixed fees							$ 23.0
Administrative Fees Expense	5.5							5.7
Indemnification Deductible									$ 0.6