Fair Value Measurements - Financial Assets and Liabilities that are Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions | Dec. 31, 2016 | Sep. 30, 2016 | Dec. 31, 2015 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | $ 154 | $ 72.7 | $ 58.4 |
Derivative financial instruments, liabilities | | (68.5) | (105.4) | (177.8) |
Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Non-qualified supplemental postretirement grantor trust investments | [1] | 34.2 | 33 | 31.7 |
Fair Value, Measurements, Recurring | Commodity contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 124.5 | 54.9 | 30.5 |
Derivative financial instruments, liabilities | | (65.5) | (98.6) | (168) |
Fair Value, Measurements, Recurring | Foreign currency contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 26 | 17.8 | 25.4 |
Derivative financial instruments, liabilities | | (0.2) | (2.4) | |
Fair Value, Measurements, Recurring | Interest rate contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | | | 0.6 |
Derivative financial instruments, liabilities | | (2.8) | (3.9) | (9.8) |
Fair Value, Measurements, Recurring | Cross-currency swaps | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 3.5 | | 1.9 |
Derivative financial instruments, liabilities | | | (0.5) | |
Fair Value, Measurements, Recurring | Level 1 | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Non-qualified supplemental postretirement grantor trust investments | [1] | 34.2 | 33 | 31.7 |
Fair Value, Measurements, Recurring | Level 1 | Commodity contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 62.7 | 28.9 | 19.7 |
Derivative financial instruments, liabilities | | (53.1) | (76.8) | (70.5) |
Fair Value, Measurements, Recurring | Level 1 | Foreign currency contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 0 | 0 | 0 |
Derivative financial instruments, liabilities | | 0 | 0 | |
Fair Value, Measurements, Recurring | Level 1 | Interest rate contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | | | 0 |
Derivative financial instruments, liabilities | | 0 | 0 | 0 |
Fair Value, Measurements, Recurring | Level 1 | Cross-currency swaps | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 0 | | 0 |
Derivative financial instruments, liabilities | | | 0 | |
Fair Value, Measurements, Recurring | Level 2 | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Non-qualified supplemental postretirement grantor trust investments | [1] | 0 | 0 | 0 |
Fair Value, Measurements, Recurring | Level 2 | Commodity contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 61.8 | 26 | 10.8 |
Derivative financial instruments, liabilities | | (12.4) | (21.8) | (97.5) |
Fair Value, Measurements, Recurring | Level 2 | Foreign currency contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 26 | 17.8 | 25.4 |
Derivative financial instruments, liabilities | | (0.2) | (2.4) | |
Fair Value, Measurements, Recurring | Level 2 | Interest rate contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | | | 0.6 |
Derivative financial instruments, liabilities | | (2.8) | (3.9) | (9.8) |
Fair Value, Measurements, Recurring | Level 2 | Cross-currency swaps | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 3.5 | | 1.9 |
Derivative financial instruments, liabilities | | | (0.5) | |
Fair Value, Measurements, Recurring | Level 3 | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Non-qualified supplemental postretirement grantor trust investments | [1] | 0 | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Commodity contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 0 | 0 | 0 |
Derivative financial instruments, liabilities | | 0 | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Foreign currency contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | 0 | 0 | 0 |
Derivative financial instruments, liabilities | | 0 | 0 | |
Fair Value, Measurements, Recurring | Level 3 | Interest rate contracts | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | | | 0 |
Derivative financial instruments, liabilities | | 0 | 0 | 0 |
Fair Value, Measurements, Recurring | Level 3 | Cross-currency swaps | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | | | | |
Derivative financial instruments, assets | | $ 0 | | $ 0 |
Derivative financial instruments, liabilities | | | $ 0 | |
| |
[1] | Consists primarily of mutual fund investments held in grantor trusts associated with non-qualified supplemental retirement plans. | |