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ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Changes in accumulated other comprehensive loss by component, net of taxes |  |  |
Balance at the beginning of the period | $ 755.3 | $ 677.2 | $ 494.9
Net gain in prior service cost |  |  | 0.8
Amortization of prior service cost | (4.5) | (4.7) | (4.0)
Amortization of net loss (gain) | 2.7 | 1.1 | 1.7
Other adjustments | (0.6) |  | 0.2
Balance at the end of the period | 805.7 | 755.3 | 677.2
Comprehensive Income (Loss): |  |  |
Tax benefit (expense) on other comprehensive income (loss) | (0.3) | 0.2 | (4.4)
Pensions |  |  |
Changes in accumulated other comprehensive loss by component, net of taxes |  |  |
Balance at the beginning of the period | (55.8) | (40.6) |
Reclassification adjustment related to the Tax Act |  | (9.2) |
Amortization of prior service cost | (1.7) | (1.7) |
Amortization of net loss (gain) | 5.6 | (4.3) |
Balance at the end of the period | (51.9) | (55.8) | (40.6)
Post Retirement |  |  |
Changes in accumulated other comprehensive loss by component, net of taxes |  |  |
Balance at the beginning of the period | 21.7 | 15.6 |
Reclassification adjustment related to the Tax Act |  | 3.4 |
Amortization of prior service cost | (2.6) | (2.9) |
Amortization of net loss (gain) | (2.8) | 5.6 |
Balance at the end of the period | 16.3 | 21.7 | 15.6
Non-Qualified Plans |  |  |
Changes in accumulated other comprehensive loss by component, net of taxes |  |  |
Balance at the beginning of the period | (0.1) | (0.3) |
Reclassification adjustment related to the Tax Act |  | (0.2) |
Amortization of prior service cost | (0.1) | (0.1) |
Amortization of net loss (gain) | (0.2) | 0.5 |
Balance at the end of the period | (0.4) | (0.1) | (0.3)
Other |  |  |
Changes in accumulated other comprehensive loss by component, net of taxes |  |  |
Balance at the beginning of the period | (0.3) | 0.4 |
Amortization of prior service cost | (0.1) |  |
Amortization of net loss (gain) | 0.1 | (0.7) |
Other adjustments | (0.6) |  |
Balance at the end of the period | (0.9) | (0.3) | 0.4
Accumulated Other Comprehensive Income (Loss) |  |  |
Changes in accumulated other comprehensive loss by component, net of taxes |  |  |
Balance at the beginning of the period | (34.5) | (24.9) | (23.6)
Reclassification adjustment related to the Tax Act |  | (6.0) |
Amortization of prior service cost | (4.5) | (4.7) |
Amortization of net loss (gain) | 2.7 | 1.1 |
Other adjustments | (0.6) |  |
Balance at the end of the period | $ (36.9) | $ (34.5) | $ (24.9)

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