| ACQUISITIONS (Summary of Acquisition-Related Expenses) (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
| Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013 | |
| Business Combination, Separately Recognized Transactions [Line Items] | ||||
| Salaries and employee benefits | $ 28,040 | $ 17,912 | $ 57,666 | $ 35,878 | 
| Professional services | 1,442 | 663 | 2,497 | 1,387 | 
| Total | 4,661 | 919 | 17,829 | 919 | 
| StellarOne Bank [Member] | ||||
| Business Combination, Separately Recognized Transactions [Line Items] | ||||
| Salaries and employee benefits | 1,158 | 7,988 | ||
| Professional services | 124 | 900 | 3,595 | 900 | 
| Other costs of operations | 3,379 | 19 | 6,246 | 19 | 
| Total | $ 4,661 | $ 919 | $ 17,829 | $ 919 | 
| X | ||||||||||
| 
- 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. 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Definition The aggregate amount of expenditures for salaries, wages, profit sharing and incentive compensation, and other employee benefits, including equity-based compensation, and pension and other postretirement benefit expense. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition This element represents a sum total of expenses not separately reflected on the income statement for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition A fee charged for services from professionals such as doctors, lawyers and accountants. The term is often expanded to include other professions, for example, pharmacists charging to maintain a medicinal profile of a client or customer. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 |