Financial Instruments and Derivative Instruments - Fair Value on a Recurring Basis (Details) - Fair value measured on a recurring basis - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Assets
Plan assets for deferred compensation	$ 2.5	$ 2.6
Total assets	7.5	9.1
Liabilities
Plan liabilities for deferred compensation	2.5	2.6
Redeemable financial instrument	2.8	2.8
Total liabilities	5.3	5.4
Interest Rate Swaps
Assets
Derivative outstanding	4.8	6.5
Forward exchange contracts
Assets
Derivative outstanding	0.2
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Plan assets for deferred compensation	2.5	2.6
Total assets	2.5	2.6
Liabilities
Plan liabilities for deferred compensation	2.5	2.6
Total liabilities	2.5	2.6
Significant Other Observable Inputs (Level 2)
Assets
Total assets	5.0	6.5
Significant Other Observable Inputs (Level 2) | Interest Rate Swaps
Assets
Derivative outstanding	4.8	6.5
Significant Other Observable Inputs (Level 2) | Forward exchange contracts
Assets
Derivative outstanding	0.2
Significant Unobservable Inputs (Level 3)
Liabilities
Redeemable financial instrument	2.8	2.8
Total liabilities	$ 2.8	$ 2.8