Seismic Data Library - Summary of the net book value of the Company’s seismic data library (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	$ 74,542	$ 115,922
U.S. Offshore [Member]
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	165	168
Unconventional 3D [Member] | U.S. Onshore [Member]
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	57,697	96,457
Unconventional 3D [Member] | Canada [Member]
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	12,215	16,361
Conventional 3D [Member] | U.S. Onshore [Member]
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	3,234	2,103
Conventional 3D [Member] | Canada [Member]
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	86	154
2D [Member] | Canada [Member]
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	291	415
2D [Member] | Mexico [Member]
Long-Lived Assets Held and Used [Line Items]
Net seismic data library	$ 854	$ 264