Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Deferred tax assets:
Net operating loss carryforwards, or NOLs	$ 27,212	$ 34,824
Goodwill	0	1,049
Worker's compensation and other current accruals	15,487	17,178
Disputed receivables reserved	6	2,521
Deferred compensation	4,504	7,478
Foreign contribution taxes	5,615	3,100
Foreign tax credits	0	186
Nonqualified stock options and SARs	7,538	6,048
Other	2,212	3,133
Total deferred tax assets	62,574	75,517
Valuation allowance for foreign tax credits	0	(186)
Valuation allowance for NOLs	(26,353)	(31,916)
Net deferred tax assets	36,221	43,415
Deferred tax liabilities:
Depreciation	(558,915)	(558,346)
Unbilled revenue	(3,216)	(347)
Mobilization	(3,939)	(2,181)
Undistributed earnings of foreign subsidiaries	(24)	(15,023)
Other	(141)	(219)
Total deferred tax liabilities	(566,235)	(576,116)
Net deferred tax liability	$ (530,014)	$ (532,701)