Supplemental Financial Information - Prepaid Expenses and Other Current Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Prepaid Expenses And Other Current Assets [Line Items]
Rig spare parts and supplies	$ 57,558	$ 52,637
Deferred mobilization costs	38,074	74,659
Prepaid insurance	12,549	12,417
Deferred tax assets	8,619	6,800
Prepaid taxes	5,950	37,612
FOREX contracts	3,627	1,262
Other	9,722	7,183
Total	$ 136,099	$ 192,570