Restructuring Costs Restructuring Costs Recognized (Details) - USD ($) $ in Millions | 3 Months Ended |
Mar. 31, 2020 | Mar. 31, 2019 |
Restructuring Cost and Reserve [Line Items] | | |
Accelerated Share Based Compensation | $ 0.2 | $ 8.4 |
Restructuring and related costs incurred in the period | 1.4 | 21.4 |
Restructuring and Related Cost, Cost Incurred to Date | 110.8 | |
Restructuring Costs, Expected Costs | 0.2 | |
General and Administrative Expense [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 1.4 | 20.3 |
Net gain (loss) from asset sales [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | 1.4 |
Interest and other income (expense) [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | (0.3) |
One-time Termination Benefits [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 1 | 6.8 |
Restructuring and Related Cost, Cost Incurred to Date | 45.6 | |
Restructuring Costs, Expected Costs | 0 | |
One-time Termination Benefits [Member] | General and Administrative Expense [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 1 | 6.7 |
One-time Termination Benefits [Member] | Net gain (loss) from asset sales [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | 0.1 |
One-time Termination Benefits [Member] | Interest and other income (expense) [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | 0 |
Lease Termination Costs [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | 0.6 |
Restructuring and Related Cost, Cost Incurred to Date | 1.6 | |
Restructuring Costs, Expected Costs | 0 | |
Lease Termination Costs [Member] | General and Administrative Expense [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | 0.6 |
Lease Termination Costs [Member] | Net gain (loss) from asset sales [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | 0 |
Lease Termination Costs [Member] | Interest and other income (expense) [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | 0 |
Accelerated Share Based Compensation [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Accelerated Share Based Compensation | 0.6 | 8.8 |
Restructuring and related costs incurred in the period | 0.2 | 8.4 |
Restructuring and Related Cost, Cost Incurred to Date | 23.8 | |
Restructuring Costs, Expected Costs | 0 | |
Accelerated Share Based Compensation [Member] | General and Administrative Expense [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0.2 | 6.9 |
Accelerated Share Based Compensation [Member] | Net gain (loss) from asset sales [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | 1.5 |
Accelerated Share Based Compensation [Member] | Interest and other income (expense) [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | 0 |
Retention Expense [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0.2 | 6.1 |
Restructuring and Related Cost, Cost Incurred to Date | 38.5 | |
Restructuring Costs, Expected Costs | 0.2 | |
Retention Expense [Member] | General and Administrative Expense [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0.2 | 6.1 |
Retention Expense [Member] | Net gain (loss) from asset sales [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | 0 |
Retention Expense [Member] | Interest and other income (expense) [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | 0 | 0 |
Pension curtailment [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | (0.5) |
Restructuring and Related Cost, Cost Incurred to Date | 1.3 | |
Restructuring Costs, Expected Costs | $ 0 | |
Pension curtailment [Member] | General and Administrative Expense [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | 0 |
Pension curtailment [Member] | Net gain (loss) from asset sales [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | (0.2) |
Pension curtailment [Member] | Interest and other income (expense) [Member] | | |
Restructuring Cost and Reserve [Line Items] | | |
Restructuring and related costs incurred in the period | | $ (0.3) |