Supplemental Financial Information (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Prepaid expenses and other current assets
Rig spare parts and supplies	$ 52,637	$ 50,288
Deferred mobilization costs	74,659	76,868
Prepaid insurance	12,417	9,587
Deferred tax assets	6,800	9,557
Deposits	1,549	827
Prepaid taxes	37,612	20,347
FOREX contracts	1,262	4,326
Other	5,634	5,353
Total	$ 192,570	$ 177,153