Employee Benefit Plans US Pension Assets, Fair Value Measurement by Input Level (Details) - UNITED STATES - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	$ 1,596.8	$ 1,456.8
Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	304.4	315.5
Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	393.6	316.9
Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	898.8	824.4
U.S. Large Cap
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	95.2	83.0
U.S. Large Cap | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
U.S. Large Cap | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
U.S. Large Cap | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
U.S. Large Cap | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	95.2	83.0
U.S. Small Cap
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	47.8	18.9
U.S. Small Cap | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	23.0	18.9
U.S. Small Cap | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
U.S. Small Cap | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
U.S. Small Cap | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	24.8	0.0
Global
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	299.1	290.3
Global | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Global | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Global | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Global | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	299.1	290.3
International
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	28.3	24.6
International | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
International | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
International | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
International | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	28.3	24.6
Emerging Markets
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	50.4	44.1
Emerging Markets | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Emerging Markets | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Emerging Markets | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Emerging Markets | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	50.4	44.1
U.S. Government and Agencies
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	199.0	257.4
U.S. Government and Agencies | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	199.0	257.4
U.S. Government and Agencies | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
U.S. Government and Agencies | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
U.S. Government and Agencies | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Corporate
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	391.1	311.2
Corporate | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Corporate | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	391.1	311.2
Corporate | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Corporate | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
State and Municipal Securities
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	2.5	5.7
State and Municipal Securities | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
State and Municipal Securities | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	2.5	5.7
State and Municipal Securities | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
State and Municipal Securities | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Opportunistic Credits
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	196.5	192.0
Opportunistic Credits | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Opportunistic Credits | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Opportunistic Credits | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Opportunistic Credits | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	196.5	192.0
Real Estate
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	108.4	102.8
Real Estate | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Real Estate | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Real Estate | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Real Estate | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	108.4	102.8
Private Equity Direct Investments
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	57.7	53.5
Private Equity Direct Investments | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Private Equity Direct Investments | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Private Equity Direct Investments | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Private Equity Direct Investments | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	57.7	53.5
Private Equity Funds of Funds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	38.4	34.0
Private Equity Funds of Funds | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Private Equity Funds of Funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Private Equity Funds of Funds | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Private Equity Funds of Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	38.4	34.0
Hedge Funds of Funds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets		0.1
Hedge Funds of Funds | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets		0.0
Hedge Funds of Funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets		0.0
Hedge Funds of Funds | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets		0.0
Hedge Funds of Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets		0.1
Cash Equivalents
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	82.4	39.2
Cash Equivalents | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	82.4	39.2
Cash Equivalents | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Cash Equivalents | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	0.0	0.0
Cash Equivalents | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	$ 0.0	$ 0.0