Transactions With Related Parties (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Sandhill Group LLC
Related Party Transaction [Line Items]
Due from related parties	$ 300		$ 300		$ 300
Poseidon Oil Pipeline Company
Related Party Transaction [Line Items]
Due from related parties	1,500		1,500		$ 1,900
Revenue from Related Parties	$ 1,979	$ 1,980	$ 5,935	$ 1,980