EMPLOYEE RETIREMENT PLANS (Details) (USD $) | 12 Months Ended |
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 |
Defined Benefit Plan Disclosure [Line Items] | ' | ' | ' |
Percentage of pool participation (in hundredths) | 30.00% | 30.00% | 30.00% |
Other benefit plans expenses (including 401(k)) allocated to the Company | $1,457,211 | $1,822,925 | $1,523,675 |
Pension Plans [Member] | EMC Insurance Group, Inc. [Member] | ' | ' | ' |
Assets [Abstract] | ' | ' | ' |
Prepaid pension and postretirement benefits | 18,310,029 | 1,413,104 | ' |
Liability [Abstract] | ' | ' | ' |
Pension and postretirement benefits | -3,401,045 | -3,800,987 | ' |
Net amount recognized | 14,908,984 | -2,387,883 | ' |
Amounts recognized in the Company's consolidated balance sheets under the caption "accumulated other comprehensive income", before deferred income taxes [Abstract] | ' | ' | ' |
Net actuarial loss | -7,605,752 | -23,299,008 | ' |
Prior service (cost) credit | -34,482 | -49,643 | ' |
Net amount recognized | -7,640,234 | -23,348,651 | ' |
Amounts that will be amortized from accumulated other comprehensive income (loss) in next fiscal year [Abstract] | ' | ' | ' |
Amortization of net actuarial loss | 81,483 | ' | ' |
Amortization of prior service (cost) credit | 9,695 | ' | ' |
Amounts recognized in the Company's consolidated statements of comprehensive income [Abstract] | ' | ' | ' |
Net actuarial gain (loss) | 15,693,256 | 1,620,026 | ' |
Prior service (cost) credit | 15,161 | 87,981 | ' |
Net amount recognized | 15,708,417 | 1,708,007 | ' |
Components of net periodic benefit cost [Abstract] | ' | ' | ' |
Net periodic benefit cost | 3,013,316 | 4,115,440 | 2,983,679 |
Pension Plans [Member] | EMC Insurance Companies [Member] | ' | ' | ' |
Change in projected benefit obligation [Abstract] | ' | ' | ' |
Benefit obligation at beginning of year | 247,290,081 | 225,100,396 | ' |
Service cost | 13,212,796 | 12,386,021 | 11,527,452 |
Interest cost | 7,656,037 | 8,818,790 | 9,703,193 |
Actuarial loss | -14,458,374 | 14,251,377 | ' |
Benefits paid | -14,591,200 | -13,266,503 | ' |
Medicare subsidy reimbursements | 0 | 0 | ' |
Plan amendments | 0 | 0 | ' |
Projected benefit obligation at end of year | 239,109,340 | 247,290,081 | 225,100,396 |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value plan of plan assets at beginning of year | 240,033,882 | 209,926,692 | ' |
Actual return on plan assets | 48,623,187 | 27,715,290 | ' |
Employer contributions | 14,684,459 | 15,658,403 | ' |
Benefits paid | -14,591,200 | -13,266,503 | ' |
Fair value of plan assets at end of year | 288,750,328 | 240,033,882 | 209,926,692 |
Funded status | 49,640,988 | -7,256,199 | ' |
Components of net periodic benefit cost [Abstract] | ' | ' | ' |
Service cost | 13,212,796 | 12,386,021 | 11,527,452 |
Interest cost | 7,656,037 | 8,818,790 | 9,703,193 |
Expected return on plan assets | -17,150,462 | -14,925,445 | -15,506,042 |
Amortization of net actuarial loss | 5,962,361 | 6,808,576 | 3,528,096 |
Amortization of prior service cost | 50,329 | 291,152 | 432,134 |
Net periodic benefit cost | 9,731,061 | 13,379,094 | 9,684,833 |
Weighted-average assumptions used to measure the benefit obligations [Abstract] | ' | ' | ' |
Discount rate (in hundredths) | 4.17% | 3.24% | ' |
Weighted-average assumptions used to measure the net periodic benefit costs [Abstract] | ' | ' | ' |
Discount rate (in hundredths) | 3.24% | 4.13% | 5.00% |
Expected long-term rate of return on plan assets (in hundredths) | 7.25% | 7.25% | 7.50% |
Expected future benefit payments to be paid from the plans over the next ten years [Abstract] | ' | ' | ' |
2014 | 21,632,278 | ' | ' |
2015 | 24,410,864 | ' | ' |
2016 | 19,469,861 | ' | ' |
2017 | 20,228,563 | ' | ' |
2018 | 20,981,451 | ' | ' |
2019 - 2023 | 113,113,599 | ' | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 288,750,328 | 240,033,882 | 209,926,692 |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | ' | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' | ' |
Defined benefit plans, vest years of service | '3 years | ' | ' |
Defined benefit plan, age of attainment years | '55 years | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value plan of plan assets at beginning of year | 240,033,882 | ' | ' |
Fair value of plan assets at end of year | 288,750,328 | 240,033,882 | ' |
Weighted-average assumptions used to measure the benefit obligations [Abstract] | ' | ' | ' |
Rate of compensation increase (in hundredths) | 4.73% | 4.73% | ' |
Weighted-average assumptions used to measure the net periodic benefit costs [Abstract] | ' | ' | ' |
Rate of compensation increase (in hundredths) | 4.73% | 4.73% | 4.73% |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 288,750,328 | 240,033,882 | ' |
Defined Benefit Plan, Estimated Future Employer Contributions [Abstract] | ' | ' | ' |
Defined Benefit Plan Estimated Future Parent Total Contributions Next Fiscal Year | 15,000,000 | ' | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Bond and Mortgage Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 32,842,844 | 29,689,019 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 32,842,844 | 29,689,019 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | U.S. Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 110,278,544 | 123,183,685 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 110,278,544 | 123,183,685 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | International Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 62,839,927 | 46,927,216 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 62,839,927 | 46,927,216 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | U.S. Bond Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 60,200,104 | 34,412,351 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 60,200,104 | 34,412,351 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Real Estate Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 13,758,266 | ' | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 13,758,266 | ' | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Short-Term Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 7,672,422 | 1,199,931 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 7,672,422 | 1,199,931 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Real Estate Securities Fund [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 1,158,221 | 4,621,680 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 1,158,221 | 4,621,680 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 1,158,221 | 4,621,680 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 1,158,221 | 4,621,680 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Bond and Mortgage Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | U.S. Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | International Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | U.S. Bond Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Real Estate Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | ' | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | ' | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Short-Term Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Real Estate Securities Fund [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 1,158,221 | 4,621,680 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 1,158,221 | 4,621,680 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 287,592,107 | 235,412,202 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 287,592,107 | 235,412,202 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Bond and Mortgage Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 32,842,844 | 29,689,019 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 32,842,844 | 29,689,019 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | U.S. Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 110,278,544 | 123,183,685 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 110,278,544 | 123,183,685 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | International Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 62,839,927 | 46,927,216 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 62,839,927 | 46,927,216 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | U.S. Bond Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 60,200,104 | 34,412,351 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 60,200,104 | 34,412,351 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Real Estate Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 13,758,266 | ' | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 13,758,266 | ' | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Short-Term Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 7,672,422 | 1,199,931 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 7,672,422 | 1,199,931 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Real Estate Securities Fund [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Bond and Mortgage Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | U.S. Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | International Stock Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | U.S. Bond Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Real Estate Separate Account [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | ' | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | ' | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Short-Term Funds Pooled Accounts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Real Estate Securities Fund [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
Non-Qualified Pension Plan [Member] | EMC Insurance Companies [Member] | ' | ' | ' |
Defined Benefit Plan Disclosure [Line Items] | ' | ' | ' |
Defined benefit plans, vest years of service | '3 years | ' | ' |
Plan assets exceeded the accumulated benefit obligation [Abstract] | ' | ' | ' |
Projected benefit obligation | 10,856,004 | 11,931,828 | ' |
Accumulated benefit obligation | 10,485,220 | 10,889,563 | ' |
Fair value of plan assets | 0 | 0 | ' |
Weighted-average assumptions used to measure the benefit obligations [Abstract] | ' | ' | ' |
Rate of compensation increase (in hundredths) | 4.68% | 4.68% | ' |
Weighted-average assumptions used to measure the net periodic benefit costs [Abstract] | ' | ' | ' |
Rate of compensation increase (in hundredths) | 4.68% | 4.68% | 4.68% |
Postretirement Benefit Plans [Member] | Gross [Member] | ' | ' | ' |
Expected future benefit payments to be paid from the plans over the next ten years [Abstract] | ' | ' | ' |
2014 | 4,863,986 | ' | ' |
2015 | 3,030,138 | ' | ' |
2016 | 3,095,475 | ' | ' |
2017 | 3,210,403 | ' | ' |
2018 | 3,339,653 | ' | ' |
2019 - 2023 | 17,222,818 | ' | ' |
Postretirement Benefit Plans [Member] | Medicare Subsidy [Member] | ' | ' | ' |
Expected future benefit payments to be paid from the plans over the next ten years [Abstract] | ' | ' | ' |
2014 | 566,889 | ' | ' |
2015 | 0 | ' | ' |
2016 | 0 | ' | ' |
2017 | 0 | ' | ' |
2018 | 0 | ' | ' |
2019 - 2023 | 0 | ' | ' |
Postretirement Benefit Plans [Member] | Net [Member] | ' | ' | ' |
Expected future benefit payments to be paid from the plans over the next ten years [Abstract] | ' | ' | ' |
2014 | 4,297,097 | ' | ' |
2015 | 3,030,138 | ' | ' |
2016 | 3,095,475 | ' | ' |
2017 | 3,210,403 | ' | ' |
2018 | 3,339,653 | ' | ' |
2019 - 2023 | 17,222,818 | ' | ' |
Postretirement Benefit Plans [Member] | EMC Insurance Group, Inc. [Member] | ' | ' | ' |
Change in projected benefit obligation [Abstract] | ' | ' | ' |
Plan amendments | 26,936,515 | ' | ' |
Assets [Abstract] | ' | ' | ' |
Prepaid pension and postretirement benefits | 4,810,529 | 0 | ' |
Liability [Abstract] | ' | ' | ' |
Pension and postretirement benefits | 0 | -26,913,646 | ' |
Net amount recognized | 4,810,529 | -26,913,646 | ' |
Amounts recognized in the Company's consolidated balance sheets under the caption "accumulated other comprehensive income", before deferred income taxes [Abstract] | ' | ' | ' |
Net actuarial loss | -6,827,263 | -15,133,387 | ' |
Prior service (cost) credit | 30,828,393 | 4,554,453 | ' |
Net amount recognized | 24,001,130 | -10,578,934 | ' |
Amounts that will be amortized from accumulated other comprehensive income (loss) in next fiscal year [Abstract] | ' | ' | ' |
Amortization of net actuarial loss | 462,971 | ' | ' |
Amortization of prior service (cost) credit | 3,316,777 | ' | ' |
Amounts recognized in the Company's consolidated statements of comprehensive income [Abstract] | ' | ' | ' |
Net actuarial gain (loss) | 8,306,124 | 491,692 | ' |
Prior service (cost) credit | 26,273,940 | 508,273 | ' |
Net amount recognized | 34,580,064 | 999,965 | ' |
Components of net periodic benefit cost [Abstract] | ' | ' | ' |
Net periodic benefit cost | 2,911,785 | 3,287,184 | 2,111,176 |
Postretirement Benefit Plans [Member] | EMC Insurance Companies [Member] | ' | ' | ' |
Change in projected benefit obligation [Abstract] | ' | ' | ' |
Benefit obligation at beginning of year | 155,102,015 | 144,354,348 | ' |
Service cost | 6,299,916 | 6,150,118 | 4,602,488 |
Interest cost | 6,171,884 | 6,536,842 | 5,998,581 |
Actuarial loss | -18,581,923 | 4,086,259 | ' |
Benefits paid | -2,587,765 | -2,787,354 | ' |
Medicare subsidy reimbursements | 305,971 | 579,650 | ' |
Plan amendments | -96,704,413 | -3,817,848 | ' |
Projected benefit obligation at end of year | 50,005,685 | 155,102,015 | 144,354,348 |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value plan of plan assets at beginning of year | 57,815,079 | 53,446,305 | ' |
Actual return on plan assets | 11,548,326 | 5,656,128 | ' |
Employer contributions | 500,000 | 1,500,000 | ' |
Benefits paid | -2,587,765 | -2,787,354 | ' |
Fair value of plan assets at end of year | 67,275,640 | 57,815,079 | 53,446,305 |
Funded status | 17,269,955 | -97,286,936 | ' |
Components of net periodic benefit cost [Abstract] | ' | ' | ' |
Service cost | 6,299,916 | 6,150,118 | 4,602,488 |
Interest cost | 6,171,884 | 6,536,842 | 5,998,581 |
Expected return on plan assets | -3,631,000 | -3,219,175 | -2,929,894 |
Amortization of net actuarial loss | 3,694,018 | 4,008,614 | 1,776,849 |
Amortization of prior service cost | -2,491,125 | -2,131,256 | -2,131,256 |
Net periodic benefit cost | 10,043,693 | 11,345,143 | 7,316,768 |
Weighted-average assumptions used to measure the benefit obligations [Abstract] | ' | ' | ' |
Discount rate (in hundredths) | 4.71% | 4.03% | ' |
Weighted-average assumptions used to measure the net periodic benefit costs [Abstract] | ' | ' | ' |
Discount rate (in hundredths) | 4.03% | 4.59% | 5.50% |
Expected long-term rate of return on plan assets (in hundredths) | 6.50% | 6.25% | 6.25% |
Assumed health care cost trend rate [Abstract] | ' | ' | ' |
Health care cost trend rate assumed for next year (in hundredths) | 7.50% | 7.75% | ' |
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) (in hundredths) | 5.00% | 5.00% | ' |
Year that the rate reaches the ultimate trend rate | '2024 | '2024 | ' |
One-percentage-point change in the assumed health care cost trend rate [Abstract] | ' | ' | ' |
Effect on total of service and interest cost, Increase | 2,655,000 | ' | ' |
Effect on total of service and interest cost, Decrease | -2,048,969 | ' | ' |
Effect on postretirement benefit obligation, Increase | 60,276 | ' | ' |
Effect on postretirement benefit obligation, Decrease | -60,276 | ' | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 67,275,640 | 57,815,079 | 53,446,305 |
VEBA Trust [Member] | EMC Insurance Companies [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 67,275,640 | 57,815,079 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 67,275,640 | 57,815,079 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Money Market Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 574,763 | 2,478,233 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Net asset value per share (in dollars per share) | $1 | ' | ' |
Assets, Fair Value Disclosure | 574,763 | 2,478,233 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Emerging Markets ETF [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 3,224,265 | 3,489,949 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 3,224,265 | 3,489,949 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 39,709,720 | 29,398,816 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 39,709,720 | 29,398,816 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Tax Exempt Fixed Income Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 2,865,017 | 2,908,889 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 2,865,017 | 2,908,889 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | International Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 7,674,589 | 6,666,766 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 7,674,589 | 6,666,766 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Life Insurance Contracts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value plan of plan assets at beginning of year | 12,872,426 | ' | ' |
Fair value of plan assets at end of year | 13,227,286 | 12,872,426 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 13,227,286 | 12,872,426 | ' |
Reconciliation of the plan assets measured at fair value using significant unobservable inputs (Level 3) [Roll Forward] | ' | ' | ' |
Beginning balance | 12,872,426 | 12,490,608 | ' |
Actual return on plan assets [Abstract] | ' | ' | ' |
Increase in cash accumulation value of life insurance contracts | 354,860 | 381,818 | ' |
Balance at end of period | 13,227,286 | 12,872,426 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 54,048,354 | 44,942,653 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 54,048,354 | 44,942,653 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Money Market Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 574,763 | 2,478,233 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 574,763 | 2,478,233 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Emerging Markets ETF [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 3,224,265 | 3,489,949 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 3,224,265 | 3,489,949 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 39,709,720 | 29,398,816 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 39,709,720 | 29,398,816 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Tax Exempt Fixed Income Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 2,865,017 | 2,908,889 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 2,865,017 | 2,908,889 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | International Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 7,674,589 | 6,666,766 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 7,674,589 | 6,666,766 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Life Insurance Contracts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Money Market Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Emerging Markets ETF [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Tax Exempt Fixed Income Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | International Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant other observable inputs (Level 2) [Member] | Life Insurance Contracts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 13,227,286 | 12,872,426 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 13,227,286 | 12,872,426 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Money Market Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Emerging Markets ETF [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Tax Exempt Fixed Income Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | International Equity Mutual Funds [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 0 | 0 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | 0 | 0 | ' |
VEBA Trust [Member] | EMC Insurance Companies [Member] | Significant unobservable inputs (Level 3) [Member] | Life Insurance Contracts [Member] | ' | ' | ' |
Change in plan assets [Abstract] | ' | ' | ' |
Fair value of plan assets at end of year | 13,227,286 | 12,872,426 | ' |
Fair values of the plan assets held [Abstract] | ' | ' | ' |
Assets, Fair Value Disclosure | $13,227,286 | $12,872,426 | ' |