Debt and Credit Facilities - Covenants and Default Provisions (Details) (Parent, Senior Notes Due March 1, 2011, USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2011
Parent \| Senior Notes Due March 1, 2011
Cross-default provisions
Maturity date	March 1, 2011
Maturities of debt	$ 700
Debt instrument, interest rate stated percentage	7.10%

The cash outflow for the settlement of borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, as it matures.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 18

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 20
-Subparagraph b

Name:	us-gaap_MaturitiesOfSeniorDebt
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration