Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		13 Months Ended	1 Months Ended
	Mar. 31, 2013 High Sierra	Mar. 31, 2013 Pecos	May 30, 2013 Pecos	Mar. 31, 2013 Pemex High Sierra	May 31, 2010 Associated Producers item
Legal contingencies
Amount for settlement of litigation				$ 3.1
Number of lawsuits filed					2
Amount not paid by customer for disputed transportation rate schedule		2.2
Amount requested as refund by the customer			5.5
Amount of fuel taxes and sales taxes that should have been collected from customers and remitted to taxing authority	14.9
Amount expected to be recovered from the customers, if required to pay the taxes assessed	14.1
Asset retirement obligations
Asset retirement obligations	$ 1.5