Supplemental Financial Information (Details 1) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Prepaid expenses and other current assets
Rig spare parts and supplies	$ 52,022	$ 52,637
Deferred mobilization costs	47,895	74,659
Prepaid insurance	27,558	12,417
Deferred tax assets	6,800	6,800
Prepaid taxes	15,162	37,612
FOREX contracts	2,542	1,262
Other	8,033	7,183
Total	$ 160,012	$ 192,570