Organization and Significant Accounting Policies - Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Total cost	$ 33,104	$ 33,170
Less accumulated depreciation	(20,077)	(19,421)
Total net book value	13,027	13,749
Land
Total cost	1,440	1,440
Building
Depreciable Life	39 years
Total cost	4,535	4,535
Building and leasehold improvements
Total cost	4,898	4,480
Building and leasehold improvements \| Minimum
Depreciable Life	3 years
Building and leasehold improvements \| Maximum
Depreciable Life	39 years
Field equipment
Total cost	18,006	17,746
Field equipment \| Minimum
Depreciable Life	3 years
Field equipment \| Maximum
Depreciable Life	4 years
Computer equipment and software
Total cost	2,677	3,151
Computer equipment and software \| Minimum
Depreciable Life	2 years
Computer equipment and software \| Maximum
Depreciable Life	3 years
Furniture and fixtures
Total cost	1,512	1,782
Furniture and fixtures \| Minimum
Depreciable Life	3 years
Furniture and fixtures \| Maximum
Depreciable Life	10 years
Vehicles
Depreciable Life	5 years
Total cost	$ 36	$ 36

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

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Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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