Employee Benefit Plans - Defined Benefit Pension Plans Payment (Detail) $ in Millions |
Dec. 31, 2015
USD ($)
|
|---|---|
| Defined Benefit Pension Plans | |
| Defined Benefit Plan Disclosure [Line Items] | |
| 2016 | $ 19.8 |
| 2017 | 20.0 |
| 2018 | 20.4 |
| 2019 | 20.9 |
| 2020 | 21.7 |
| Next 5 years | 122.0 |
| OPEB | |
| Defined Benefit Plan Disclosure [Line Items] | |
| 2016 | 0.4 |
| 2017 | 0.4 |
| 2018 | 0.4 |
| 2019 | 0.4 |
| 2020 | 0.4 |
| Next 5 years | $ 2.3 |