Supplemental Financial Information (Details 1) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Prepaid expenses and other current assets
Rig spare parts and supplies	$ 50,857	$ 50,288
Deferred mobilization costs	60,005	76,868
Prepaid insurance	20,409	9,587
Deferred tax assets	9,557	9,557
Deposits	1,574	827
Prepaid taxes	5,515	20,347
FOREX contracts	236	4,326
Other	9,236	5,353
Total	$ 157,389	$ 177,153

Prepaid Expenses and Other Current Assets.

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Carrying amount as of the balance sheet date of unamortized costs of insurance coverage, which will be charged against earnings ratably over the period in which contractually agreed upon coverage's will be in effect; such periods expire within one year or the normal operating cycle, if longer.

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