Information about Segment Assets by Country (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total assets	$ 3,181,018	$ 3,333,627
Asia Pacific
Segment Reporting Information [Line Items]
Assets, continuing operations	1,196,298	1,402,923
Atlantic
Segment Reporting Information [Line Items]
Assets, continuing operations	570,347	536,734
Middle East
Segment Reporting Information [Line Items]
Assets, continuing operations	1,208,121	1,006,284
Corporate and Other
Segment Reporting Information [Line Items]
Assets, continuing operations	$ 206,252	$ 387,686