Equity Method Investment (Details) (USD $)	1 Months Ended	12 Months Ended
	Apr. 30, 2012 mi	Dec. 31, 2013	Dec. 31, 2012
Equity Method Investment
Length of pipeline to be constructed (in miles)	120
Entity's equity interest in construction agreement (as a percent)	25.00%
Contribution cap	$ 250,000,000
Expected contribution in future years		143,000,000
Number of year's investment expected for contribution		3 years
Contributions		18,900,000	6,900,000
Net book value		$ 26,892,000	$ 6,915,000