Fair Value and Line Item Caption of Non-derivative Instruments (Detail) (Non-derivative instruments, USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Carrying Value of Non-derivative instrument Designated as hedging instrument	$ 823,211	$ 863,217
Foreign Currency Debt \| Long-term Debt
Derivative [Line Items]
Carrying Value of Non-derivative instrument Designated as hedging instrument	$ 823,211	$ 863,217

Aggregate notional amount of all nonderivative instruments that are designated as hedging instruments in a hedge of the net investment of foreign operations. For example, foreign currency denominated intercompany loans.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5579245-113959

Name:	us-gaap_NotionalAmountOfNonderivativeInstrumentsDesignatedAsNetInvestmentHedges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant