The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3291-108585

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 18

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 20

-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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

Name:	us-gaap_RepaymentsOfUnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Unsecured Exchangeable Senior Notes (Narrative) (Details) (2.875% Exchangeable Senior Notes [Member], USD $)	0 Months Ended			3 Months Ended
	Feb. 20, 2012	Feb. 15, 2012	Feb. 16, 2012	Mar. 31, 2012	Jan. 10, 2012
2.875% Exchangeable Senior Notes [Member]
Debt Instrument [Line Items]
Coupon/Stated Rate					2.875%
Debt instrument repurchase date by company				Feb. 15, 2012
Put Right expiration date				Feb. 08, 2012
Notes redemption date				Feb. 20, 2012
Debt instrument in connection with redemption last day to exchange notes				Feb. 16, 2012
Debt instrument redemption price percentage of principal	100.00%		100.00%
Amount paid for repurchase	$ 333,459,000	$ 242,735,000