Employee Benefit Plans - Schedule of Plan Assets Using the Fair Value Hierarchy (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 144.8	$ 125.0
Net Asset Value ("NAV")
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	129.8	111.3
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.4	1.7
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12.6	12.0
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.4	1.7
Cash and Cash Equivalents | Net Asset Value ("NAV")
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Cash and Cash Equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.4	1.7
Cash and Cash Equivalents | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Cash and Cash Equivalents | Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Insurance Group Annuity Contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12.6	12.0	$ 14.4
Insurance Group Annuity Contracts | Net Asset Value ("NAV")
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Insurance Group Annuity Contracts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Insurance Group Annuity Contracts | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Insurance Group Annuity Contracts | Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12.6	12.0
Common/Collective Trust Funds — Corporate and Other Non-government Debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22.9
Common/Collective Trust Funds — Corporate and Other Non-government Debt | Net Asset Value ("NAV")
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22.9
Common/Collective Trust Funds — Corporate and Other Non-government Debt | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Common/Collective Trust Funds — Corporate and Other Non-government Debt | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Common/Collective Trust Funds — Corporate and Other Non-government Debt | Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Common/Collective Trust Funds — Government, Corporate and Other Non-government Debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	40.2	56.3
Common/Collective Trust Funds — Government, Corporate and Other Non-government Debt | Net Asset Value ("NAV")
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	40.2	56.3
Common/Collective Trust Funds — Government, Corporate and Other Non-government Debt | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Common/Collective Trust Funds — Government, Corporate and Other Non-government Debt | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Common/Collective Trust Funds — Government, Corporate and Other Non-government Debt | Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Common/Collective Trust Funds — Customized Strategy
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.4
Common/Collective Trust Funds — Customized Strategy | Net Asset Value ("NAV")
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.4
Common/Collective Trust Funds — Customized Strategy | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Common/Collective Trust Funds — Customized Strategy | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Common/Collective Trust Funds — Customized Strategy | Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Common/Collective Trust Funds — Corporate Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50.3	55.0
Common/Collective Trust Funds — Corporate Equity | Net Asset Value ("NAV")
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50.3	55.0
Common/Collective Trust Funds — Corporate Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Common/Collective Trust Funds — Corporate Equity | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Common/Collective Trust Funds — Corporate Equity | Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0.0	$ 0.0