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BENEFIT PLANS, Fair Value of Plan Assets by Assets Category (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | $ 171,625 | $ 177,551 |
Total dividends and interest receivable excluded from plan assets |  | 400 | 300 |
Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | 159,324 | 158,365 |
Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | 12,301 | 19,186 |
Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | 0 | 0 |
Money Market Accounts [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 7,990 | 12,901 |
Money Market Accounts [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 2,240 | 431 |
Money Market Accounts [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 5,750 | 12,470 |
Money Market Accounts [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Equity Securities [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 83,868 | 109,468 |
Equity Securities [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 83,868 | 109,468 |
Equity Securities [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Equity Securities [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
U.S. Large-Cap [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 34,985 | 51,197 |
U.S. Large-Cap [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 34,985 | 51,197 |
U.S. Large-Cap [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
U.S. Large-Cap [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
U.S Mid/Small Cap [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 12,354 | 14,026 |
U.S Mid/Small Cap [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 12,354 | 14,026 |
U.S Mid/Small Cap [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
U.S Mid/Small Cap [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
CBSI Stock [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 8,393 | 15,354 |
CBSI Stock [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 8,393 | 15,354 |
CBSI Stock [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
CBSI Stock [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
International [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 28,136 | 28,891 |
International [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 28,136 | 28,891 |
International [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
International [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Fixed Income Securities [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 69,767 | 46,958 |
Fixed Income Securities [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 63,279 | 40,312 |
Fixed Income Securities [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 6,488 | 6,646 |
Fixed Income Securities [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Government Securities [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 37,885 | 13,137 |
Government Securities [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 31,397 | 6,491 |
Government Securities [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 6,488 | 6,646 |
Government Securities [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Investment Grade Bonds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 14,517 | 21,539 |
Investment Grade Bonds [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 14,517 | 21,539 |
Investment Grade Bonds [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Investment Grade Bonds [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
International Bonds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 5,085 |
International Bonds [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 5,085 |
International Bonds [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 0 |
International Bonds [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 0 |
High Yield [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [2] | 17,365 | 7,197 |
High Yield [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [2] | 17,365 | 7,197 |
High Yield [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [2] | 0 | 0 |
High Yield [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [2] | 0 | 0 |
Other Investments [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [3] | 10,000 | 8,224 |
Other Investments [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [3] | 9,937 | 8,154 |
Other Investments [Member] | Significant Observable Inputs, Level 2 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [3] | 63 | 70 |
Other Investments [Member] | Significant Unobservable Inputs, Level 3 [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [3] | 0 | 0 |
Pension Benefits [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | $ 172,026 | $ 177,865 | $ 173,416
[1] | Excludes dividends and interest receivable totaling $0.4 million and $0.3 million at December 31, 2015 and 2014, respectively.
[2] | This category is exchange-traded funds representing a diversified index of high yield corporate bonds.
[3] | This category is comprised of exchange-traded funds and mutual funds holding non-traditional investment classes including private equity funds and alternative exchange funds.

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- Definition Represents the total of interest and dividend receivable, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein. + References No definition available. + Details
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- Definition Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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