Inventories (Schedule of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventories [Abstract]
Unsold crude oil	$ 25,583	$ 51,810
Materials and supplies	141,205	190,923
Inventory, Net, Total	$ 166,788	$ 242,733	[1]

[1] Reclassified to conform to current presentation.