Restructuring Activities (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges expected to incur		$ 1,100,000
Expected cash expenditures for remainder of fiscal year		7,300,000
Write-down of excess and obsolete inventory	18,200,000
Inventory written off through scrap expense	1,100,000
Inventory write-down to a lower of cost of market value	1,900,000
Amount accrued for restructuring	4,511,000	4,511,000	5,073,000
Systems
Restructuring Cost and Reserve [Line Items]
Restructuring charges expected to incur		28,400,000
Write-down of excess and obsolete inventory	18,200,000
Number of positions eliminated	88
Number of positions eliminated, percent	31.00%
Restructuring charges	27,296,000
Systems | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	25,080,000
Systems | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,216,000
Systems | Severance charges
Restructuring Cost and Reserve [Line Items]
Amount accrued for restructuring	5,600,000	5,600,000
Restructuring charges	5,562,000
Systems | Severance charges | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3,729,000
Systems | Severance charges | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,833,000
Systems | Asset write-downs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	21,734,000
Systems | Asset write-downs | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	21,351,000
Systems | Asset write-downs | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 383,000
INOVA Geophysical [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated	77
Number of positions eliminated, percent	20.00%