Employee Retirement Plans - Net Actuarial Loss (Gain) and Prior Service Cost Included in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Net loss (gain)	$ 6.3	$ 4.9
Total recognized in net periodic benefit cost and other comprehensive income (loss)	6.3	4.9
Actuarial (gain) loss	7.9	6.7
Total recognized in other comprehensive (income) loss	$ 7.9	$ 6.7

No definition available.

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Amount, after tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount, after tax, before reclassification adjustment, of (increase) decrease in accumulated other comprehensive income of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Amount, after tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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