| ACQUISITIONS (Narrative) (Details) (USD $) | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 0 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013 | Dec. 31, 2013 | Dec. 31, 2012 | Jan. 02, 2014
 Acquisition Date, January 1, 2014 [Member]
 site | Jun. 30, 2014
 StellarOne Bank [Member] | Jun. 30, 2013
 StellarOne Bank [Member] | Jun. 30, 2014
 StellarOne Bank [Member] | Jun. 30, 2013
 StellarOne Bank [Member] | Jan. 02, 2014
 StellarOne Bank [Member]
 Acquisition Date, January 1, 2014 [Member] | Jan. 02, 2014
 StellarOne Bank [Member]
 Performing Financing Receivable [Member]
 Acquisition Date, January 1, 2014 [Member] | |
| Business Acquisition [Line Items] | |||||||||||||
| Number of shares equivalent to each share of acquired entity | 0.9739 | ||||||||||||
| Number of common shares issued | 22,147,874 | ||||||||||||
| Acquired performing loans, Fair value | $ 2,100,000,000 | ||||||||||||
| Value of Company common stock issued | 549,489,000 | ||||||||||||
| Acquired performing loans, principal and interest payments receivable | 2,500,000,000 | ||||||||||||
| Number of overlapping bank branches | 13 | ||||||||||||
| Acquired performing loans not expected to be collected | 35,400,000 | ||||||||||||
| Fair value of loans acquired with a deterioration of credit quality | 131,107,000 | 3,973,000 | 131,107,000 | 3,973,000 | 3,622,000 | 145,454,000 | 145,454,000 | ||||||
| Carry-over for allowance for credit losses | 31,379,000 | 34,333,000 | 31,379,000 | 34,333,000 | 30,135,000 | 34,916,000 | |||||||
| Acquisition and conversion costs | $ 4,661,000 | $ 919,000 | $ 17,829,000 | $ 919,000 | $ 4,661,000 | $ 919,000 | $ 17,829,000 | $ 919,000 | |||||
| X | ||||||||||
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- Definition Acquired performing loans, Fair value No definition available. 
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| X | ||||||||||
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- Definition Acquired performing loans not expected to be collected. No definition available. 
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| X | ||||||||||
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- Definition Acquired performing loans, principal and interest payments receivable. No definition available. 
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| X | ||||||||||
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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, severance and employee-related charges, systems integrations; and other related charges as well as other restructuring charges. No definition available. 
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| X | ||||||||||
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- Definition Business acquisition, number of shares equivalent to each share of acquired entity, No definition available. 
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| X | ||||||||||
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- Definition Number of overlapping bank branches No definition available. 
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| X | ||||||||||
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- Definition Number of shares of equity interests issued or issuable to acquire entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Details 
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| X | ||||||||||
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- Definition Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Definition The balance of financing receivables that were acquired with deteriorated credit quality. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Definition A valuation allowance for financing receivables that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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