Organization and Business (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 t
Westshore
Organization and Business
Escrow Deposit	6.5
Westshore | 2015 Exports
Organization and Business
Third Party Tons Sold	5,200,000
Westshore | 2016 through 2018 exports
Organization and Business
Third Party Tons Sold	6,600,000
Westshore | 2019 through 2024 exports
Organization and Business
Third Party Tons Sold	7,200,000
Westshore | Committed Capacity Q2 2015 [Member]
Organization and Business
Committed Capacity Adjustment	500,000
Westshore | Committed Capacity Second Half 2015 Member [Member]
Organization and Business
Committed Capacity Adjustment	500,000
Millennium | Equal to or less than
Organization and Business
Throughput Option	7,700,000
SSA Marine | Equal to or less than
Organization and Business
Throughput Option	17,600,000