HELD-TO-MATURITY SECURITIES (Details) (USD $)	3 Months Ended	12 Months Ended
Jun. 30, 2011	Dec. 31, 2011
HELD-TO-MATURITY SECURITIES [Abstract]
Amortized cost of held-to-maturity securities reclassified to available-for-sale	$ 1,600,000,000	$ 1,600,000,000
Fair value of held-to-maturity securities reclassified to available-for-sale	1,700,000,000	1,700,000,000
Increase in other comprehensive income due to transfers to available-for-sale securities	19,700,000
Gross gains recognized on held-to-maturity securities		$ 37,000

This item represents the unrealized gain (loss) recognized in other comprehensive income (a separate component of shareholders' equity) as a result of securities categorized as held-to-maturity being transferred to the available-for-sale securities category.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27405-111563

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13, 22

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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