Included in other assets were the following: | | | | | | | | | | | | | | September 30, 2017 | | December 31, 2016 | | September 30, 2016 | | ($ in millions) | Investments in non-consolidated affiliates | $ | 28.2 |
| | $ | 26.7 |
| | $ | 26.1 |
| Deferred debt issuance costs | 2.7 |
| | 2.6 |
| | 2.8 |
| Tax-related receivables | 13.1 |
| | 17.5 |
| | 15.8 |
| Interest rate swaps | 3.7 |
| | 7.7 |
| | 2.5 |
| Supply contracts | 1,146.3 |
| | 566.7 |
| | 572.8 |
| Other | 21.6 |
| | 23.2 |
| | 20.3 |
| Other assets | $ | 1,215.6 |
| | $ | 644.4 |
| | $ | 640.3 |
|
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