|
Seismic Data Library (Details) (USD $)
|
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
|
Jun. 30, 2012
|
Jun. 30, 2011
|
Jun. 30, 2012
|
Jun. 30, 2011
|
Jul. 01, 2012
|
|
| Property, Plant and Equipment [Line Items] | |||||
| Internal data processing costs capitalized | $ 702,000 | $ 447,000 | $ 1,349,000 | $ 902,000 | |
| Lowest amortization rate using the income forecast method | 70.00% | ||||
| Actual aggregate rate of amortization | 70.00% | ||||
| Impairment charges | $ 0 | $ 0 | |||
|
Seismic Data Library [Member]
|
|||||
| Property, Plant and Equipment [Line Items] | |||||
| Straight-line amortization period | 4 years | ||||