SELECTED QUARTERLY FINANCIAL INFORMATION (unaudited) - Additional Information (Details) (USD $) Share data in Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Sep. 30, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Special dividend, payment date	Sep. 01, 2010
Special dividend paid	$ 5,600,000,000
Regular quarterly dividend	11,000,000	323,000,000	608,000,000	127,000,000
Special dividend, number of common shares issued	324,000	0	324,319	0
REIT conversion benefit
Reversal of certain deferred income tax liabilities		$ 0	$ (1,064,000,000)	$ 0

The cash outflow from the entity's earnings to the shareholders.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (a)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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_PaymentsOfDividends
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration