Business Segments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Phillips 66 and Affiliated Companies [Member]
Segment Reporting Information [Line Items]
Percentage of net sales revenue in oil and natural gas production	14.00%	17.00%
Shell Oil and Affiliates [Member]
Segment Reporting Information [Line Items]
Percentage of net sales revenue in oil and natural gas production	20.00%	14.00%
Shell Oil [Member]
Segment Reporting Information [Line Items]
Percentage of net sales revenue in oil and natural gas production			17.00%
BP [Member]
Segment Reporting Information [Line Items]
Percentage of net sales revenue in oil and natural gas production			13.00%
Petronas [Member]
Segment Reporting Information [Line Items]
Percentage of net sales revenue in oil and natural gas production			12.00%