Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number APB14-1

-Paragraph 31

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Subsequent Events (Details) (USD $)		0 Months Ended	9 Months Ended
Subsequent Events (Details) (USD $)	Oct. 12, 2011	Oct. 19, 2011 2.50% Convertible Senior Notes Due August 15, 2013 [Member]	Sep. 30, 2011 2.50% Convertible Senior Notes Due August 15, 2013 [Member]	Dec. 31, 2010 2.50% Convertible Senior Notes Due August 15, 2013 [Member]	Mar. 31, 2008 2.50% Convertible Senior Notes Due August 15, 2013 [Member]
Subsequent Event [Line Items]
Debt instrument, principal outstanding		$ 335,000,000	$ 428,000,000	$ 428,000,000	$ 475,000,000
Convertible notes tender price		346,000,000
Share repurchase program, amount authorized	300,000,000
Convertible notes, tender offer price			1,025
Convertible notes, principal amount tendered			1,000
Tender offer expiration date			October 19, 2011
Board of Directors authorized share repurchase program	$ 300,000,000