Transactions with Related Parties (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Guaranty obligation	$ 1,900,000
Davison [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	0	$ 0	$ 1,293	[1]
Sandhill [Member]
Related Party Transaction [Line Items]
Due from related parties	300	300
Revenue from Related Parties	3,259	3,060	3,076	[2]
Poseidon Oil Pipeline Company [Member]
Related Party Transaction [Line Items]
Due from related parties	1,900
Revenue from Related Parties	$ 3,941	$ 0	$ 0	[3]
Sandhill Group, LLC [Member]
Related Party Transaction [Line Items]
Ownership percentage	50.00%

[1] (4)Amounts included in discontinued operations for all periods presented.

[2] We own a 50% interest in Sandhill Group, LL

[3] (2)We own a 64% interest in Poseidon Oil Pipeline Company, LLC.