Income Taxes (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended						12 Months Ended			15 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Sep. 30, 2012
Reconciliation of the expected income tax expense on income (loss) before income taxes using the statutory federal income tax
Expected income tax expense (benefit) at 35%							$ 30,339	$ 12,146	$ (3,464)
Foreign tax rate differential							(5,404)	(7,858)	(11,914)
Foreign tax differences							4,897	(2,511)	0
Formation of INOVA Geophysical							0	0	10,507
Nondeductible financings							0	0	1,082
State and local taxes							192	493	665
Nondeductible expenses							47	1,091	492
Deferred tax asset valuation allowance:
Deferred tax asset valuation allowance on formation of INOVA Geophysical							0	0	20,213
Deferred tax asset valuation allowance on equity in losses of INOVA Geophysical							(104)	8,002	8,303
Deferred tax asset valuation allowance on write-down of RXT shares							195	459	2,677
Deferred tax asset valuation allowance on operations							(6,305)	(1,686)	(1,619)
Income tax expense	$ 10,191	$ 6,037	$ 4,184	$ 3,445	$ 1,085	$ 147	$ 23,857	$ 10,136	$ 26,942	$ 5,420	$ 3,484