Retirement Plans - Summary of Projected Benefit Obligations in Excess of Plan Assets (Details) - Pension Plan - USD ($) $ in Millions |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Defined Benefit Plan Disclosure [Line Items] | ||
| Projected benefit obligation | $ 293.3 | $ 3.2 |
| Fair value of plan assets | $ 235.8 | $ 0.0 |