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Pension and Other Postretirement Benefit Plans (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019
PNM | Pension Plan |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Service cost | $ 0 | $ 0 | $ 0 | $ 0
Interest cost | 4,985,000 | 6,294,000 | 9,971,000 | 12,587,000
Expected return on plan assets | (7,363,000) | (8,527,000) | (14,726,000) | (17,051,000)
Amortization of net (gain) loss | 4,465,000 | 3,880,000 | 8,930,000 | 7,759,000
Amortization of prior service cost | (138,000) | (241,000) | (277,000) | (483,000)
Net Periodic Benefit Cost (Income) | 1,949,000 | 1,406,000 | 3,898,000 | 2,812,000
Contributions by employer |  |  | 0 | 0
Expected employer contributions, remainder of fiscal year | 0 |  | 0 |
Estimated employer contributions in next fiscal year | 0 |  | 0 |
Expected employer contributions in year 3 | 4,600,000 |  | 4,600,000 |
Expected employer contributions in year 4 | 19,100,000 |  | 19,100,000 |
Expected employer contributions in year 5 | 19,000,000.0 |  | $ 19,000,000.0 |
PNM | Pension Plan | Minimum |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Assumptions used calculating net periodic benefit cost, discount rate |  |  | 3.40% |
PNM | Pension Plan | Maximum |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Assumptions used calculating net periodic benefit cost, discount rate |  |  | 3.50% |
PNM | OPEB Plan |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Service cost | 10,000 | 13,000 | $ 20,000 | 26,000
Interest cost | 613,000 | 829,000 | 1,227,000 | 1,658,000
Expected return on plan assets | (1,387,000) | (1,318,000) | (2,774,000) | (2,636,000)
Amortization of net (gain) loss | 87,000 | 169,000 | 174,000 | 338,000
Amortization of prior service cost | 0 | (99,000) | 0 | (198,000)
Net Periodic Benefit Cost (Income) | (677,000) | (406,000) | (1,353,000) | (812,000)
Contributions by employer |  |  | 0 | 0
Disbursements by employer | 1,000,000.0 | 700,000 | 2,100,000 | 1,500,000
Expected employer disbursements in year 2 through 5 | 13,500,000 |  | 13,500,000 |
Total expected employer disbursements for remainder of fiscal year | 3,700,000 |  | 3,700,000 |
PNM | Executive Retirement Program |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Service cost | 0 | 0 | 0 | 0
Interest cost | 122,000 | 162,000 | 244,000 | 324,000
Expected return on plan assets | 0 | 0 | 0 | 0
Amortization of net (gain) loss | 101,000 | 79,000 | 201,000 | 158,000
Amortization of prior service cost | 0 | 0 | 0 | 0
Net Periodic Benefit Cost (Income) | 223,000 | 241,000 | 445,000 | 482,000
Disbursements by employer | 300,000 | 400,000 | 800,000 | 700,000
Expected employer disbursements in year 2 through 5 | 5,400,000 |  | 5,400,000 |
Total expected employer disbursements for remainder of fiscal year | 1,500,000 |  | 1,500,000 |
TNMP | Pension Plan |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Service cost | 0 | 0 | 0 | 0
Interest cost | 544,000 | 672,000 | 1,088,000 | 1,344,000
Expected return on plan assets | (821,000) | (967,000) | (1,642,000) | (1,934,000)
Amortization of net (gain) loss | 315,000 | 235,000 | 629,000 | 470,000
Amortization of prior service cost | 0 | 0 | 0 | 0
Net Periodic Benefit Cost (Income) | 38,000 | (60,000) | 75,000 | (120,000)
Contributions by employer |  |  | 0 | 0
Expected employer contributions in year 4 | 1,100,000 |  | 1,100,000 |
Expected employer contributions in year 5 | 2,800,000 |  | 2,800,000 |
Estimated employer contributions remainder of fiscal year through year three | 0 |  | $ 0 |
TNMP | Pension Plan | Minimum |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Assumptions used calculating net periodic benefit cost, discount rate |  |  | 3.40% |
TNMP | Pension Plan | Maximum |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Assumptions used calculating net periodic benefit cost, discount rate |  |  | 3.50% |
TNMP | OPEB Plan |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Service cost | 12,000 | 13,000 | $ 23,000 | 26,000
Interest cost | 93,000 | 113,000 | 187,000 | 226,000
Expected return on plan assets | (135,000) | (129,000) | (268,000) | (258,000)
Amortization of net (gain) loss | (80,000) | (110,000) | (162,000) | (220,000)
Amortization of prior service cost | 0 | 0 | 0 | 0
Net Periodic Benefit Cost (Income) | (110,000) | (113,000) | (220,000) | (226,000)
Disbursements by employer | 200,000 | 100,000 | 300,000 | 200,000
Estimated employer contributions for remainder of fiscal year through year 5 | 0 |  | 0 |
TNMP | Executive Retirement Program |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Service cost | 0 | 0 | 0 | 0
Interest cost | 6,000 | 8,000 | 11,000 | 16,000
Expected return on plan assets | 0 | 0 | 0 | 0
Amortization of net (gain) loss | 6,000 | 4,000 | 12,000 | 8,000
Amortization of prior service cost | 0 | 0 | 0 | 0
Net Periodic Benefit Cost (Income) | 12,000 | 12,000 | 23,000 | 24,000
Expected employer disbursements in year 2 through 5 | 300,000 |  | 300,000 |
Total expected employer disbursements for remainder of fiscal year | 100,000 |  | 100,000 |
TNMP | Executive Retirement Program | Maximum |  |  |  |
Components of Net Periodic Benefit Cost |  |  |  |
Disbursements by employer | $ 0 | $ 0 | $ 0 | $ 0

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