Other Current Assets (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Components for Other Receivables and Current Assets [Line Items]
Other receivables and current assets	$ 134,191	$ 147,402
Accounts Receivable Portion Of Annual Lease Licenses And Software Maintenance [Member]
Components for Other Receivables and Current Assets [Line Items]
Other receivables and current assets	68,300	89,900
Taxes Receivable Related To Overpayments And Refunds [Member]
Components for Other Receivables and Current Assets [Line Items]
Other receivables and current assets	$ 51,000	$ 32,900

Aggregate carrying amount, as of the balance sheet date, of current assets not separately disclosed in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer).

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 8

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.8)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_OtherAssetsCurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant